I wonder how many 8x8 assault gun variants they are testing.
The first one here a different turret design altogether. Note the small door at the back of the turret, which indicates the presence of an auto-loader. Another thing, the door geometry is very similar or identical to the auto-loader door on the ZTQ-15 light tank, which
might mean that the gun is different from the one in your image.
This one is almost identical to the vehicle in your image, but there are minor differences in the turret, but I think it's safe to say that they are the same design/variant. The turret here appears to sit lower (without the turret ring exposed), but this could be due to the angle, or maybe the vehicle in your image is atypical.
Then there is this one, which appears to feature a very large bow flap, which leads me to believe that this might be specifically designed for the Marines and unrelated to the variants in the images above.