'Campaigns and Democracy officer' don't you just love academia? What will the poor little darlings do when they have to venture out into the real world where there are all sorts of things that could scare or offend them?
Not really imo, They broke the advertising policy
"The Union has stated that the handing out of sombreros breached a key advertising policy which was sent to all stall holders before the event, prohibiting any use of stereotypical imagery in advertising."
To be fair, the University of East Anglia is not a proper university, just a glorified polytechnic, so you'd expect that kind of talk. Anyway, from reading the link I've learnt two new words today, transphobic and ableist. I'll just now have to find out what they mean.