So Alan's team is Metagross, Mega Charizard X and Houndour. Makes sense. Metagross because of Steven, Houndour because of Malva. #Sarcasm.
This is probably the start of the Team Flare concluding arc, at least the part in Lumiose City. I think we might get the end result of Ash-Greninja vs. MC-X in the beginning of this episode, after which Team Flare starts to kick things off. I don't think the league will be "interrupted" since that just does not make sense with all those strong trainers present. Instead, this will be more of a chase around Lumiose with Team Flare trying to seize Squishy. XYZ40 (Zygarde) will be the Lumiose City Team Flare clash, which will probably include Clemont's dad and his Mega Blaziken and a show of strength from Lysandre and Malva's Face/Heel-turn. Then Team Flare will probably move towards the Ultimate Weapon/Geosenge Town
and that's where Xerosic (Malamar) is, and why we see a Lucario in the episode after that (Korrina/Gurkin). Ash and Greninja can get their revenge on Alan and Charizard in XYZ43 at the end of the Team Flare 5-parter.
Seems like an incredible arc to watch.
It's a shame that they haven't set up AZ, but it's something I can live with.
Or how about this.
Ash loses to Alan last ep and everyone goes their merry way with this being a fresh start.
Ash finally goes back to Johto to capture that Houndour!