Well if you look at the list of Pokemon that was found from the coding in X/Y, you'll realize that all of them have now been used except for AZ's floette.
These were all found prior to the announcement of ORAS, so we know the Mega Latis were debuted in those games. The Vivillon patterns were released as events not long after, both in 2014. Diancie, Hoopa, and Volcanion were also released as events following the discovery, they were more spaced out but to this date they have all now been officially revealed and released. Now that just leaves AZ's Floette still unused which makes me think they still have a purpose for it, they just haven't shown it yet.
Sun & Moon's theme is something to do with flowers, that's been pretty evident with a lot of the reveals over the past few months and more obviously when it was teased during that interview with one of the Marketing Directors in 2015. I don't know how exactly they plan to release this event, but I have a strong suspicion that AZ will fit into the storyline of S/M and that is when we will either receive or encounter AZ's Floette.