This tank is not a Clan Wars reward. In fact, there are three tanks in development: this one, Chieftain MK.6 and Chieftain/T95 (CW reward).
The tank has a "premium" mark in the game at the moment, though it is likely a disinformation by WG in order to heat the things up.
Type: "Premium" MT.
Crew: 4 (Loader, Driver, Gunner, Commander)
An interesting fact: all three models are historically accurate because T95 and Chieftain had interchangeable parts.
In-Garage Overview (with stats, armor; Russian voiceover and GUI)