Look, with how much they've been pushing the non-main anime short form series (Twilight Wings, PokéToon, Evolutions, Hisuian Snow) in the last two years, I do believe we are at the very least heading for Ash being phased out as the protagonist. Team Rocket is rarely appearing at all after becoming a staple of the anime, and they even had a retirement scare very recently. I wouldn't put it past them to actually have Ash win the Masters Tournament and either replace him as the protagonist, or end the main anime right there after 25 years - in favor of straightforward anime adaptations of Scarlet/Violet and all subsequent Pokémon games from then on.
Whatever they do is fine with me, I haven't kept up regularly with the anime since the S/M era. But if they do replace Ash, I reckon it's going to be quite a shocker - for better or for worse, especially if it comes with the end of the main anime. None of us is ready for that.