Why diversity is important to the university
For the university, diversity means that the campus is viewed as a welcoming environment for anyone who wants to apply. Having an inclusive mission at an educational institution says something progressive and important about their campus that they value diversity and will allow their students to express themselves as they see fit.
A university’s mission statement will usually include some type of inclusive language about their educational philosophy, and if it doesn’t then you should look further into why they don’t. National development relies on a society that is inclusive and accepting of diverse populations, so most every college will have this language.
Don’t just accept their mission statement at face value, though. Look into their student activities, clubs, and campus organizations to make sure there are funds and students dedicated to a mission that are also important to you, for example, an LGBTQ+ office or Office of Diversity and Inclusion.