The only way Robotech would impact Macross is if HG wants to license it, but then that's a whole new problem with music licensing, which involves money, and I don't see too many companies wanting to jump on that train in the current economic state of things.
Robotech is going off on it's own with the live-action. And as I've said many times, things are probably going to be redesigned since I don't see how a 80's cartoon design works for a live-action movie.