I couldn't care less what the title is or what console it's on, since I play to buy a PS4 anyways and IMO that would make FFV13 that much better anyways, but since you seem to want an opinion since no one really knows the definite answer yet, I'll say yes. Why? The Fabula Nova Cristallis or whatever the hell it's called has already begun to dissolve. My guess is that it's part of the reason 0-Type was renamed also. The "13" saga was never supposed to have sequels originally as far as I know. So keep the other 2 as their own games and make the Trilogy the only ones associated with 13.
That's what I think. --- The Official Maverick Hunter Zero of the MvC3 board! PSN: Darth-Griever