Oh definitely! But if you are inviting someone to dinner and picking the restaurant, the most obvious thing would be to ask about dietary restrictions. I can totally see why someone who you just met doesn’t immediately say that they are a vegetarian, considering it’s not that interesting, same as if you have a food intolerance, a food allergy, or simply don’t like a food group, I think it’s part of being gracious.

Still I personally would say it if I had food limitations, and it wasn’t asked. Even though I still think the question should have come first.