I think everyone just uses different terms to mean the same thing, and vice versa (same to mean different). If they want to call them just "full remakes", then there's no point adding anything. However, they have to acknowledge the Mega Evolution they added, and keep that going with new discoveries, so it has officially gone beyond just "remakes". If they add new Pokémon anywhere (no, they won't do this as a rule, but even one somewhere), then it's no longer just a remake. Keep in mind I'm allowing for Sinnoh-found babies appearing where their parents would have appeared normally as being part of a "remake". But even just adding Mega Evolution and new forms of the legendaries means these are new games in an old region, not just remakes.
And from the sounds of it, Diancie's Mega Stone (which is a new item obviously) is the chief new addition, that and the event Diancie somewhere. I'm guessing Volcanion will come in Z, and Hoopa in Delta Emerald, presuming these are announced. If they are not, expect events.