M235i is likely to get an xDrive option because it already exists in the M135i, though I expect it won't be engineered for RHD for us UK drivers (too too bad for us)
M2 and M2GC, highly unlikely. That's why BMW have created the whole M Performance range, so they don't have to dliute the top M cars with stuff like softer riding, xDrive etc.
So that's what we've been told anyway. Didn't stop them making the X5M and X6M (yes I know they're a necessary revenue generating evil, bla bla bla)