No. Internally it does that when you use x/y/z, scale_x/y/z or pan/tilt/roll, but you cannot change the matrix directly by script.

GameStudio does implement some matrices functions though, like multipling two matrices or creating the identity matrix, but that's it. The only thing they are imported for now is when using the new material effects. Transforming the model's UVs is also done in effects only.