Cuban BTR-100: BTR-60 hull with a modified T-55 turret, could come as a squadron or event vehicle.
BMPT-72: Could come as a tank destroyer. The 4 atgm limit would have been a problem, but now tank destroyers get the ammo box so the 4 atgms will no longer be a problem.
BMP-3 Manul: modified bmp-3 hull with the engine in the front and an unmanned turret with 30mm cannon and Korent atgms. This could be at the end of the light tank line at BR 10.7
I mean, the low rank Andrusha/Katusha also can do some serious damage in the right moment and with right amount of lack, but it all too specific and rare to make it anything more than a gimmick