I'm a big Muse fan generally, and I thought they were superb in 2004 and 2010, and pretty good in 2016 (I know most people don't agree) but the last couple of albums have been all over the place and despite them remaining big amongst a particular fanbase, I think booking them again for Glastonbury would be so tiresome and stale.
Tend to agree with the general thoughts on Pulp here. If there was a time for them to have done it, it would have been last year. And although I like somewhat in a bubble where they are massive/seminal/widely known/legendary, I do think their cross-over appeal with Gen Z is pretty tenuous. When I saw them at Manchester Castlefield and Finsbury Park last year they were both sell-out crowds and both shows were tremendous, but I didn't see many people under 30 there...