Butterfree will never return. Now he has a family. They probably had a baby.But I would love to see it with 1 episode family.Maybe even give 1 baby to ash. LolI wonder for how long have people asked for Butterfree, Primeape, and Pidgeot to return...?
Because if it is since they left, then that is really sad.
In my case I wished for Butterfree to return since I was, like, 12, and now I am almost 32.
Primeape is in training He will come back one day. But in this series, Ash has 2 fighting type pokemons. Ash will likely catch Urshifu as well. He does not return in this series.
One of the most ambiguous subjects in the anime is Pidgeot. I think if he will, he should return in this series. But he was never mentioned. Ash has a promise to pidgeot to get you back.
Primeape is still Ash's pokemon. Others were released. They may not return.