>>49769261I think they are school uniforms, they change with version so maybe your version decides what school you go to and what will be your rival school
The thing is ash already graduated from pokemon school thanks to kukui, and assuming im right you can't put him as a student in one school because the other would look bad, so here is my what i guess could happen
>Sakuragi becomes a teacher the gen 9 schools>ash and goh(or another character) remain sakuragi's assistants but now they also get to interact with the students of these pokemon schools>Eventually for whatever reason ash and goh end up representing the schools in some way and the finale is an ash vs goh battle 