Maybe. It depends on what your definition of "Git" is. I would say that it is not the same, because a "git p4" repository behaves differently when you talk to the upstream. 

My comment was meant to note the potential bug where you have a Git repo but change the dependency to "git_p4" after fetching once. I haven't tested, but I believe that in that case Rebar would behave as if everything was fine, silently ignoring the repository change.