I went to Columbia. I’m not a Dartmouth booster. I just know they have a good CS department. There are a lot of other schools with good CS departments I might rec, but this is what is on the table. Your friend from HS notwithstanding, I still think OP should ask Dartmouth directly to be put in touch with people who might be able to speak to this. On these sites, I worry a little that people on waitlists might be pushing narratives for their own ends so I think it’s fair to ask for details.