SQUEALS! (then after remembering what most typical video game anniversaries bring) Oh, hmm, yes, very nice.
As a totally crazy idea, assume they won't just have compilation collections and mobile spin-offs, and announce variations on the following: a solid release period for
XII Zodiarc Brave, release window for
VIIR and announcements concerning future installments in the VIIR series, an all-new spin-off entry (maybe Type-1 or similar) with new characters and a new world, maybe a proper
Final Fantasy X-3 that will conclude the narrative of Tidus and Yuna, and most unlikely of all a teaser trailer showing the planned visual style and main protagonist (hopefully female) of
Final Fantasy XVI and announcing it for current gen platforms.
I think
XV DLC and Stormblood are givens. Probably say something like: Tune in for more announcements and updates at E3 2017. Then who knows, show us a teaser that displays something even we're not expecting!
If he is there, it'd be nice if they used his placeholder clothing from pre-2011 Versus days, so much more KH-ish than his current outfit.