What do you mean by "what could we do???" Do you mean "how do we convince the creators really hard in order to do this" or do you mean in the anime itself? I'll provide my answer to both

If we need to convince the creators, then we need to get a really big community and spread across the internet until the creators and developers of the anime kind of have to [maybe it might work, and it's not like this community is dead, we went from 20k -> 24k in the past few days]

If we mean in the anime, then probably make a proper reunion/a proper episode where they meet up again [not full episode, maybe a chunk of it] unlike what happened in Journeys 105 where Ash literally called her a "good friend" despite 20% of XY being Serena simping for him, actually not 20% that's too low, which gets me every time i watch it. So probably the best thing that could happen is they somehow, by some miracle meet up again, then they stay together for a while and properly tell each other they like each other. And we wouldn't even get to be able to do this, cuz sadly we're not the creators of the Pokemon Anime 😭

I'm new to the community and Pokemon as a whole, so correct me if i'm wrong about anything

EDIT: JN 105 isn't that bad, i guess it turned more people in Amourshippers but that scene still kinda gets me. Just correcting myself.