I don't think Demolishor or Rampage are ever refered to by their toy names, so I think it's unlikely it will be changed.

I don't actually care anyway. The fans know who they are, and those who aren't into the toys can call them what they want.

It's not like all other movie credits are perfect either - staying within TFs, the original animated movie listed about 10 characters who didn't even get a line in the film!