When I was at Microsoft, one of the things I tried to persuade the Outlook / Exchange team to do was allow dietary preferences to be stored in Exchange and exposed as part of a meeting invitation reply then aggregated and presented.

Any time someone organised a catered event, they always sent out an invitation that asked people to provide dietary preferences in a reply. This led to two very different flows:

If you have no dietary restrictions, you hit 'accept' or 'decline'.

If you had dietary restrictions, you hit 'accept...' and then entered your dietary restrictions in the email.

As a vegetarian, it was mildly annoying to say 'I will attend and I am still vegetarian' each time I replied. But vegetarian is the simplest case.

Imagine your dietary restrictions are Halal or Kosher. Now your reply is 'I will attend and, yes, I'm still Jewish / Muslim'. Now you've got a flow that is harder for people of certain religions. A competent lawyer could argue that this is religious discrimination.

But it gets worse. A lot of dietary restrictions are related to medical issues. So now you're requiring people to specify their medical conditions ('I will attend and, yes, no one has found a cure for celiac disease yet') in an email, every time they want to reply to a meeting. Now imagine that you have to comply with a legal requirement to delete all information related to a specific person's medical conditions. Can you do that? No, because these emails are all interleaved with normal emails. If this were built in, the person organising the event could have a view of what dietary requirements they have to cater for, not linked to individuals (though linkable if you have multiple catered meetings with overlapping sets of people), which could be automatically deleted after the event.

If you're selling corporate groupware, I'd suggest you get this right and advertise it as a differentiating feature.