If you guys never went out to eat or they just told you it was a diet but it was actually a lifestyle choice. Would you want to know it was a lifestyle choice instead of a diet? Would you care that they didn't eat meat?
Sure, imagine you'd be having a dinner date... you would need to be able to take that into account :D Apart from that, no problem as long as she wouldn't oblige me to become a vegetarian as well. I would eat vegatarian with her on certain days, but I'd want to eat my steak or chicken on others!
Uhhhhh yea I'd want to know. What if he comes over and I order a meat lovers pizza, or my mom cooks dinner and she always cooks some kind of meat, or what if I invite him to a barbeque and then I feel like a insensitive cunt. Just let me know. As long as they're not forcing me to go vegetarian or vegan too then I'm fine.
I would definitely want to know if she is vegan as meat with vegans if they haven't eaten meat for a long time can result in a nasty bowl aches. As in like doubling over I would feel so miserable if my date went through that. Also as a partner I'd make sacrifices to adapt to the needs.
I would want to know. It's not necessarily a deal breaker. Unless they're a super psycho ultra insane "ethical" vegetarian/vegan. If they were then it'd be a deal breaker. I don't need that backwards bullshit nonsense in my life.