The episode with the Dance Party, there has been 2 names come up, Get one and Catch one. It could be an egg, even though Serena's Eevee will probably evolve.
I don't see this dance party being a performance, but more of a fun get together or something. Serena could get an egg ect.
Swirlix was the one fairy type I could see Ash catching, but at this point, I would be slightly annoyed by it. Although it seems to be Ash's, I can see Serena getting Swirlix instead, because of the rivalry between Miette and her.
I don't think Miette will give a Swirlix to him though. Although it would further the rivalry between her and Serena. Not to mention, Serena bakes. I don't see Clemont catching it, but I wouldn't put it past the writers. If one person catches a pokemon and evolves, the others are soon to follow. Because that is how the pattern as gone so far in this series. When one catches a pokemon, the others catch one with in a few episodes. When one evolves, the others have a pokemon evolve. Clemont is the only one who hasn't had a new pokemon since the Luxray, so he is due for one.
Also, Ash is known for catching some pokemon who have already evolved, such at Krookodile and Noctowl, who are possibly two of his most remembered pokemon. Also, he caught Snorunt late and it evolved before the Hoenn League.
We also haven't had an old character return yet and I have a feeling that we will have a filler arc between Kalos League and whatever is next, if there is a 7th Gen anime with Ash.