Most schools have systems in place to keep track of kids. Some do a better job of gathering and processing data points from different sources. I love @RoonilWazlib99 description of Proctor’s system - it sounds so comprehensive.
My sense is that most schools have added mental health services and awareness training for the community. Many let students take mental health days. Most try to get out in front of situations that may be challenging. (My kid’s school did a “how to talk to your family about applying to college” program before Thanksgiving, for example.)
Some of this ends up being serendipity. If your kid gets a dorm parent they connect with, if their advisory group clicks, a coach takes a special interest – all great. Programs and processes are wonderful but it’s humans who deliver. And some kids really try NOT to connect, so it’s not just the school.
If anyone is asking this as they are applying, definitely explore this – as well as the whole philosophy around supports, culture, etc – where you are applying. Some schools are all-in in creating a family environment while others prefer to give the kids room to create family/community on their own and want adults there for support as needed. (Btw, both approaches work really well.) Some approaches or environments may just feel more right for your kid and your family.