Only what I've seen on TikTok mate, which is quite a bit actually. I think some things should be allowed, and indeed expected at festivals, and certainly condemning Israel and supporting the people of Palestine fall within that sphere. Even the "Maggie's in a box" chanting from last weeks show is probably OK even if it did push the boundaries of what may be considered common decency. But the video I saw of them brandishing on stage the Hamas flag whilst leading chants of Up Hamas, up Hezbolah, crossed a line for me mate. Especially given the events that took place at a similar music festival just 18 months ago.
As regards writing music, I'm not aware that this is an actual issue here unless things have been said I don't know about. But for me any song lyrics that incite hate or actual violence against a group or race shouldn't be allowed. Not sure if that counts as Orwellian. I guess it's a grey area.
Presumably Sharon Osborne is Jewish. I didn't know that. I know that if I was Jewish I'd be pretty much ashamed of what Israel is doing in Palestine. Plus she has a short memory. A number of years ago the RSPCA were less than happy about what her own husband was getting up to on stage.