>>58263106Because OLM wasn't in control of what GameFreak planned to to later down the line, and Ash Greninja only existed as a concession for circumstances that were purely retarded and could've been avoided.
Literally, LITERALLY all they had to do was let Ash bring back one of his older mons so he could Mega Evolve it, and that would've solved the problem of "how is the protagonist of the Pokemon anime supposed to promote the main mechanic of Pokemon XY?"
But no, they wasted Charizard's comeback on a literal filler arc in Unova, when by that point they were absolutely in the know about Mega Evolution, Mega Charizard X & Y, and everything else they could've capitalized on with everyone's favorite starter.