It seems a little early to be writing off Alton Towers just yet, given it is currently the only UK park that we know has actual new ride investment going in for 2025. Unless I'm mistaken, I don't think any of the other UK park's have had anything announced for next year yet, other than the stage in Thorpe Park.
And all the developments going in to all the UK parks seem to involve cuts to ride numbers. Remember Hyperia replaced four rides (with one relocated) and the new plans for Chessington also currently involve four attractions being replaced by two (not an exact science I know, given some of them might crop up elsewhere, replacing other attractions).
I think it's just the time of year when there's a lot of chopping and changing going on - admittedly more so than normal and it feels slightly more brutal at Alton given we've recently had announcements regarding future additions at Thorpe and Chessington, whereas all Alton future plans are old news at this point given that we've known about Project Horizon and Ocean for ages at this point.
Ghostly Manor at Paultons