I've been reading about this too and apparently the stroke he had in '23 left him paralysed on his right side from his shoulder down, but he was able to recover to about 70% of full movement.
That's gonna be tough for anyone to deal with at any point in their lives, but when you are internationally famous for being a drummer all your life, it's gotta add an extra dimension of hurt to you.
From what I understand, he's only retiring from touring, so hopefully it's not the last we'll hear from him.
Mark