I think that a lot of people (if not most) will agree that the choice of the Aufklärungspanzer Panther for the tier 7 light tank in its supertest incarnation was not a good one. Let's quickly sum up the (potential) bad sides:

- the Panther hull is too big
- the vehicle is bulky, hard to hide (eg. no passive scouting)
- the vehicle is potentially undergunned (50mm L/60 as stock, tier 5 105mm howitzer and the gold-requiring konisch gun)
- the vehicle is potentially underpowered (850hp will most likely not cut it, the 1150hp turbine would perhaps help)
- considering its speed and its size, its armor is probably insufficient
- potantially bad depression (long hull, low turret)
- completely unhistorical with the VK2801 turret

Of course this design has one big advantage for Wargaming: pretty much no new modelling work is needed, as the hull and turret models are already there (Panther hull, Leopard and VK2801 turret). The costs of creating such a vehicle are kept to a minimum. By the way, a friend told me that he believes at this moment Wargaming is in the cost-cutting phase, eg. making new patches (including vehicles) as cheaply as possible. Let's recap 8.4 then - 2x Panzer I, Panzer II (remodelled existing Panzer II), Valentine AT (Valentine hull already existed), Churchill GC (well, Churchill hull model was also already there), the whole AT series with vehicles looking similiar - less modelling work, then there's the AT-15 model used for AT-15A and (modified) for Tortoise. Oh yes, and the second FV215b with a remodelled turret. Looks like Wargaming has gone eco friendly and is into recycling right now :) When you look at the 8.5 patch - what will we get: a recycled Panther, RU251 (new, granted), 2 Leopards, 1 recycled VK3002DB(v1) and the (new, granted) Indienpanzer.

But this is not what this article is about. It is about the possible alternatives to the T7 Aufklärungspanzer Panther. There are several in fact. We are looking at 1944+ vehicles to keep at least some historical continuity (T6 VK2801 is a late 1943 project while T7 scout Panther was concieved in early 1942). We have basically three options (with a few more bit obscure ones).
Panzer 38(t) mit Panzer IV-Turm

This is a concept project by Krupp. In November 1944, Krupp sent a batch of projects to the Inspector-general of the tank force (Panzertruppen), proposing to re-arm existing tank designs. The basic idea was to use the best weapon available with the least amount of armor, so weight is saved and the vehicle is maneuverable. Krupp believed that the vehicle should have enough armor to actually protect itself from its own weapon. In January 1945, the Inspector-general passed the proposals to the Waffenprüfamt 6, who in turn threw most of them out, because so many new designs were unrealistic to produce. For Germany it was too late anyway, but some of these proposals were technically very interesting.
One of the proposals was to put a Panzer IV turret on the redesigned Panzer 38t hull and re-arm it with the L/48 75mm KwK 40 cannon (lower picture). It was deemed technically possible to mount the turret at the cost of reduction of the hull angle and armor, but the weight would stress the roadwheels immensely. The vehicle (projected to weight 16 tons) would thus have little mobility advantage, compared to the Hetzer hull. The armor would be roughly comparable to the Hetzer (60mm front, cca 20mm sides).
Now, three things could make it viable for scouting:
a) more powerful engine (originally, Tatra T103 was intended, but 220hp doesn't really cut it for 16 tons)
b) the Panzer IV turret can hold a 105mm howitzer (eg. firepower comparable to the Aufklärungspanzer Panther)
c) the PAW 600.
PAW600 (as shown on the upper picture) was historically considered (as it was very light), but for World of Tanks it has one main disadvantage: it's a smoothbore weapon. Wargaming would probably deny it on that basis only. There are other options however (the same that could apply for the Aufklärungspanzer Panther) - 50mm autocannons for example.
Aufklärungspanzer 38d

The history of this project is quite interesting. The first "incarnation" of the Aufklärungspanzer 38 was built on the 38t chassis and armed with a 20mm Flak 38 gun at BMM in Prague in early 1944. This is how it looked:

50 were made. They served from 1944 till the end of the war But the 20mm firepower was not enough. It was decided to arm the 38t chassis with a 75mm L/24 gun. Two projects were made in Prague. In September 1944 - one was concieved under under the designation of Gerät 564. It was basically a Bergepanzer 38t hull with the short 75 mounted on the top of it. On 29.9.1944, it was tested in Kummersdorf. Some sources state the prototype was tested also in early 1945 in Denmark. The second project was done by BMM - it was notably higher:

Both projects had different powerplants, giving them around 150hp. But this was only the beginning. The 38t chassis had one major issue (in Germans' eyes at least). Due to different techniques used in Czechoslovakia, it was very hard, expensive and impractical to manufacture the hull in Germany. And so it was that in September 1944, the OKH announced they want a new 38t - based tank destroyer and a scouting vehicle (the TD would be produced by Alkett in 1000 pieces per month, the scout vehicle would be produced by Miag in 300 pieces per month). In fact, the 38t chassis was so successful that in October 1944, the Panzerkomission declared that the only vehicles to be produced from now on would be based on Tiger, Panther and 38t chassis.
For the aforementioned reasons (and because by the end of the war, Škoda fell behind with 38t chassis production - partly due to war damage, partly due to sabotage, partly simply because it lacked materials), it was decided to rework the 38t chassis into what would become the 38d. The new re-worked chassis was 60mm wider, it had stronger springs and sturdier construction. The main reason for it was of course the Jagdpanzer 38d, but the scouting development was not neglected. The Aufklärungspanzer variant of 38d chassis was projected to be fitted with a (Czech) 220hp Tatra T103 engine, giving it the speed of 52 km/h. In January 1945, on the meeting of the Panzer development commission it was decided that the Aufklärungspanzer 38d would be produced in 2 variants: with a turretted 20mm (using the Hängelafette mount) and the non-turretted 75mm AKF L/48. Both versions were to be produced simultaneously using 1:1 ratio. The vehicle was projected to weight 14 tons, with the frontal armor being cca 30mm thick (sloped at 50 degrees), the sides were cca 20mm thick. The 75mm gun was a re-worked PaK 40 with different mount and construction - it was lighter, allowing for better handling and aiming and it could be traversed 20 degrees to each side. The official designation of the AKF was "AK 7 B84" - its development was finished in April 1945 and only 4 were made.
Originally, this vehicle was scheduled for production from January 1945, but bureaucratic delays killed it. By March 1945 the production order was still not given and by then, it was all over. In late March 1945, an order was given to redirect all the 250 scheduled 38d chassis for emeregency Jagdpanzer 38d production. In two months, the war was over.

In World of Tanks, this vehicle could server as a sort of slower T7 AMX ELC. It's rather low silhouette could provide excellent camo bonus to compensate for its relatively lower speed and thin armor. The weaponry choice is potentially also very wide: there's the 20mm (obviously for stock version), then there's the 38t's 75mm L/24, the main option would be the 75mm AKF, and... to save the best for last: one Bergepanzer 38t (a lot similiar to the Aufklärungspanzer 38t chassis) was converted in December 1944 by BMM Prague to carry a 150mm s.I.G.33/2 howitzer. That could be give it a great derp option. Here's how it looked:

I think such a gun could be mounted on the 38d chassis too.

Spähpanzer SP I.C.
(thanks for bringing this design up, Okinoshima)

This is obviously a post-war prototype design, based on the Schützenpanzer Kurz (Hotchkiss), which was built from 1959 to 1967 by Magirus-Deutz in Mainz. It was concieved in 1956 during the slow building of the new German army - the Bundeswehr. The intent was to follow the footsteps of the popular and successful wartime Puma armored car - a very lightly armored vehicle with a massive weapon for its size. The project was being worked on from 1956 to 1962 (the prototype was built in 1961) - after that it was cancelled, because the vehicle was deemed too light for modern battlefield needs.

The added weight of the gun and turret required some changes to the hull, engine and drivetrain. The rifled 90mm Mercar gun had only a short recoil, allowing it to be mounted in such a small turret. The vehicle weighted 6,5 tons, the armor was 8-15mm thick and it was powered by a 200hp Hotchkiss-Brandt engine (giving it a whopping 30hp/t), the maximum speed was projected at 58 km/h. The gun was the mentioned 90mm Mercar, firing impressive HEAT rounds. It was projected for the crew of 3.
Historically, it would be a good predecessor to the RU251, most likely very nimble and light, with a killer gun.

There are exotic options. The Porsche Typ 245-010, or for example the Aufklärunspanzer Porsche Typ 245-011.

Honestly, I doubt Wargaming will remove the Aufklärungspanzer Panther at this point - the 0.8.5 is too close (relatively). But perhaps this example shows that recycling old models is not exactly the best solution.