What is it with having to ask people their dietary requirements now? Surely if you are allergic/vegetarian/vegan etc you would just say up front? Organising a dinner for work and having to double check with everyone if they have dietary requirements - one has now replied to say their vegetarian. Surely you would mention it when replying?
It's reminding me that when I was organising DD's birthday party one of the parents hadn't told me that their DD was celiac - I only found out because a mutual friend told me. I hadn't been checking if they had dietary requirements because I thought they would just tell me up front.
So - AIBU - I should always check OR AINBU - they should say themselves