As I suspect you know, there are lots of eating disorders that do not lead you to being underweight.
I think it is a great time to be a nutrition major. Right now the world seems open to testing and rewriting all the nutrition rules. Some coaches are going to be ok with you knowing more than them in this area and some coaches will worry that you spend too much time thinking about what you eat or that your experimental eating habits are under cutting their training.
Having said that, worrying about what your future coach will think about you being vegan a year ahead of time is a behavior that could be on the list of things that would support the idea that you have a tendency toward an eating disorder. Most coaches are not going to pick up on this. However, as you go through the recruiting process, there are going to be lots of reasons you don't like schools and lots of reasons schools are not interested in you.
I think the best thing to keep in mind is that in the beginning, schools and athletes use single clear problems to rule athletes and schools out. But after you narrow things down to the best 3 or 4 schools, your final choice is likely due to an overall impression, and any of those schools will be good choices. For example, a choice between a little more scholarship money with a nagging suspicion of anti-veganism vs a little less money but being vegan never really came up vs next to no money but the coach is also vegan. All of those could work out fine, you are just going to have to go with your best guess.