I...honestly never thought they'd pull this trigger. Ash has been around for so long, I just assumed he'd always be part of the show, somehow or another. I was halfway expecting them to make him a Professor in the Trainer School for the Scarlet/Violet saga, after winning the league again in Ultimate Journeys.
I really SHOULDN'T be shocked. This entire Journeys saga has kind of felt like a long goodbye to Ash. Collecting all the Pokemon. Winning the League. He's done everything he set out to accomplish. The writing's been on the wall for a while now. But still...I'm a little shocked. And, I know a lot of people are going to disagree with me, but I don't know if changing the protagonist will really be worth it or not.
I mean, no matter who the protagonist is, we're still going to be doing the same things we've been doing for the past 26 years. We're still going to see them collect gym badges, and explore the world in filler episodes. I'm not sure if the overall quality of the show will really change no matter who the lead character is. They're just getting rid of a long-running character just for the shake of change....when that "change" will probably be 80% the same, either way. Unless they DRASTICALLY change the plot, it's still going to feel repetitive.
On the other hand, I DO think some of the specials they've done have been higher quality than the main show for a while now. The Hisuian Snow, Poketoons, and anniversary shorts they put up on Youtube were all more unique than the main anime has been in a while. If they can bring some of that energy into the main show, I'd be a improvement. Maybe that's the plan.
And it's not like Ash is some great character, he's really rather "generic shonen protagonist". He's just been such a...CONSISTENT presence, it's hard to believe he's really not going to be the star of the show anymore. It's going to be a weird change to get used to. It's kind of bittersweet.