Reading through this thread, and people are getting way too hung up on the word "reboot" (which is understandable, since I don't think anyone, even Hollywood, knows what it means at this point).
But the way I see it is, we were never going to get a direct sequel to Predators, so whether the new movie is advertised as a reboot or sequel or whatever its going to be its own thing just like all three films to date have been.