A festival being "appalled" is ludicrous. A festival is not a person. What the article actually means is that Glastonbury PR has decided to condemn the comments and chant as they don't think it fits their brand.
I've had enough of having to pretend the "opinions" of companies and entities matter. They are just a business and will go along with the perceived status quo to protect their business interests. Their stance on anything is bullshit and they should be told to shut up - we don't need Glastonbury telling us what we can or can't hear or think.
Whether you agree with what was said or not, we really need to push back against the corprotisation of opinion and discourse.