I just asked my daughter about this. For whatever it’s worth, she reacted very strongly and said she can’t imagine anyone at Notre Dame not being accepting of LGBTQ students. She feels the students there are very accepting of others. I agree with girish 21 that some of what the university publishes may not be completely in sync with the views of its student body. Also agree with Suzy100 that the dating pool might be smaller, so I would take some time to consider that. Below are some local South Bend links that might be of interest to you. Good luck with your college search 
https://sites.google.com/thelgbtqcenter.org/home/our-story/about-us?authuser=0
https://visitsouthbend.com/events/south-bend-pride-2018/
http://www.newnownext.com/pete-buttigieg-wedding-south-bend-indiana/06/2018/