We all know the Lightning inclusion into XIV has raised quite a stir in the community. If Yoshi-P announced that in patch 2.3 they were adding another former prominent character from the series, how would you feel about that?
Knowing how Lightning is being implemented, I would be ok with it. Its optional, I won't see dead characters in there, and it doesn't seem to be tied to the main storyline. I'll start flipping tables tho if Sephiroth makes his way in though. I am sure I will see enough variations of him in game!