>>30695308True. Ash's Charizard no sold a Dragon Rush from Iris's Dragonite overpowered him with Slash. If he used Dragon Claw, he would have killed that Dragonite.
If Ash's Zard does return, he should get a mega. Megas are prominent in the post game as nearly every named trainer has one, so Ash should be able to get his own. Even random scrub trainers in the battle tree have megas. He finally has the means to do it with his Z-Ring. Not to mention that Mega Glalie was in the early SM anime promotion.
Then there's Ash referencing his old pokemon in SM. He even mentioned the many Tauros he's caught to Lillie. XY was isolated, and he never brought up his old mons. Even Oak and Delila didn't appear until the very end of XYZ. Despite how shit it was, even BW wasn't as isolated from the rest of the series as XY and XYZ. Since SM isn't afraid to bring up past events, that makes it likely for Ash's old mons to return.