So explain to me something, because I'm totally tech illiterate. In XY we learned about 12 megas before the game was released, and then found out there were 28 afterwards when it was released.

In the ORAS demo we found the entire index list of megas, and it's composed of every single mega that was announced plus the 2 exclusive to the demo steelix and glalie. What I want to ask is is it possible Gamefreak anticipated datamining and intentionally omitted all unannounced megas? Or would that be impossible, traces of them would stay behind if they were there to begin with? It just seems bizarre they'd announce every single one.