>>21306779Updating XY wouldn't give the XY user the mega stones, it would make it so that they could go online and fight somebody with mega Metagross.
I think one of the problems they encountered was how to handle trainer models, for both XY and ORAS.
In FRLG and Emerald there were sprites for the Hoenn Trainer and Kanto Trainer respectively, that's all it was, a sprite. With the hacking tool nobody found anything for a Hoenn Trainer and since customization is out of ORAS there's no need to code in what a Kalos Trainer would look like.
It's still bullshit that two Gen 6 games can't play against each other because of a lack of a fail safe. They fucking knew they were going to remake Hoenn.