I really hope he uses Kingler at some point. It's a given that he'll use Muk, as he has done in the past, against Bellsprout in the Indigo Plateau and against Gary's Blastoise.
I can see Ash tactically setting up his team now, unlike against Gary he just had his team based on power, and in Hoenn he uses his Pokémon he caught there (And Charizard let's not forget).
But, don't get your hopes up on Charizard, Squirtle, Pidgeot, Primeape, etc. Yeah he said he'll come back for Pidgeot & Primeape, but there was also a whole GS Ball story that went out the window. So, the writers have moved on. So should we. The only time I'd ever see Pidgeot coming back, would of been in a movie. But we're like, what 14 movies in now? And they don't mean as much as the first 3. I said my goodbyes a while back, and Staraptor is a good replacement.
Although, saying that. If there was a 'slim' chance of bringing back Charizard. It's because I can't see Ash using Gible against Paul, at all. So there is a space left open for you know who. We can hope.