No bid is going to be perfect, but it would be better in future if this sort of thing was identified at the bid stage, and maybe we should try and find out which of these options are needed and by how many.
As for Mexico, may I suggest they make it easy for those that want to avoid pork to do so as well as those who want to avoid other meat. There are also going to people who will want to know if they have considered offering a vegan option and if so whether they will do so.
Personally I like Mexican cuisine and look forward to eating Mexican food, I suspect most attendees will also be fairly flexible re food - if there are only a small number for whom special arrangements need to be made then surely that is a diversity issue which we should make arrangements for?