>there are people who think the demo will leak everything again
0 chance of this happening for a new gen, don't be stupid

ORAS demo was a completely different situation, it was a remake meaning there wasn't much to leak in the first place and by the time the demo released we already knew all the mega evolutions. The only significant leak was Hoopa's new form, everything else was small in the grand scheme of things. Also, the 3DS hacking scene was kind of in its baby stages during that time so it was likely not seen as a huge risk