Of course him meeting Infernape won't stop him from getting more Pokemon but the theory about Ash getting at least one new Pokemon per generation probably isn't going to happen.Even with Ash's Infernape coming back, I don't believe that Ash is completely done catching Pokémon. We are still too early in the series and after hopefully beating Iris, Ash still has ranks 100>9 to go through.
He has yet to capture Pokémon from Johto, Hoenn, Unova, Kalos, and Alola in this series and I think they'll likely be fully evolved Pokémon like Dragonite and Gengar so they don't have too spend too much time on them from their base forms.
Personally, I think they should be Espeon, Beautifly, Beartic, Gogoat, and Alolan Sandslash.
Espeon could appear as an Eevee that Ash and Dragonite save from danger and due to the immense kindness shown by both, she ends up evolving in the same episode. It can also play into the huge contrast between her and Chloe's Eevee and maybe have Ash and Chloe genuinely converse to each other.
I chose Beautifly for Hoenn as Ash got a Dragonite after Iris owned one, so I wondered what he can "copy" from May. Beautifly works due to the fact that the writers trolled Goh by giving him three Dustox. Maybe Ash can get a shiny Beautifly or something idk.
For Unova, I chose Beartic as it doesn't overlap with any of his own Unova Pokémon and besides Glalie, Ash is seriously suffering in the Ice-type. Maybe it can be a Beartic that lost it's title as leader of the clan and grew to respect Ash and chose to go with him instead. It can be the new Hawlucha.
For Kalos, Gogoat can suit him well. He was enamored with Alexa's Gogoat and Noivern and they gave him Noivern in XY so it's Gogoat's turn. It can be his land rideable Pokémon as Dragonite is his air one.
For Alola, I just gave him Alolan Sandslash as a counterpart to Lillie's Vulpix and like stated before, he needs more Ice types. I don't think the other Alolan forms fit him well other than Raichu.
Like even ignoring that I disagree with all of your choices for his next captures I don't see how he could handle 5 more Pokemon at minimum with the ones he's already got that could definitely use more training and battles. And sorry but screw rotation. I'm sick of that being the same excuse every time as if we haven't learned from that dumpster fire in the Black and White saga.