I'm questioning whether Paul and a past poke-girl are indeed returning. It all comes back to this interview that came out a few months ago (Was it a few months ago, I'm sure someone will correct me if I'm wrong) In the interview, the person they interviewed did bring up Paul a lot, and that got me really curious. Personally I think Paul could be one of Ash's rivals during the Kalos-league and I mean it's clearly stating during a DP episode of sorts that Paul has travelled through most, if not, all of the regions by that point. Also it could be interesting to see how he handles mega evolution.
Also they posed a question similar to this near the end :
If a main female travelling companion was to return who would you want it to be?
Personally I would find it odd if they asked this question without eventually bringing back the person that was the most demanded, I dunno, they still haven't brought Iris back for her two episodes so maybe their planning something?
I would love to hear everyone's opinions.