So, about Polina and college. First, I don't think walking into classes in the rain on a fairly small campus constitutes undue hardship for a skater--Canadians and Russians do fine in much more severe circumstances. Second, does she even live in a dorm or is she in a sorority house? Either way, she lives close to where she trains, which seems the main thing. Third, yes, she has a class schedule, but she has some choice about which classes she takes and when and, given that she attended multiple competitions last season, she clearly manages some sort of work-around. I'm sure she also works out her rink practice time so that it aligns with her schedule. If anything, a college schedule is easier to work around than a high-school schedule--and Polina attended a high school.
It's different than performing in theater where a lot of people have to be on the same rehearsal/performance schedule for months on end. There are a lots of serious college athletes--you see tons of them every Summer Olympics. The only difference between them and Polina is that she and her family have had to do it mostly on their own. I, personally, had a college housemate who was one of the top 25 female marathon runners in the world. Injuries, not college, did in her athletic career.
As for full-time training--if you read the interview, Polina says that she'll be done with college before 2022 and plans to train full-time at that point--*if* her foot can handle it. She actually has no other post-college plans.
It's worth noting that even with the recurring injury and the lack of the flip and lutz, Polina was comfortably in seventh after the short. She was one of the few who skated a clean program and the GOE on her elements was good. If you want to see where she started, check out her skate in Vacaville last summer. There were some very rough skates, but she improved every single outing. While attending college full time.
I just don't see any sign that attending college is the issue. The foot is the issue. And it's a serious one. Hope it continues to heal solidly.
One last thing--I think getting an education and having outside interests is a good thing for skaters--because no one skates forever. Good for Mirai Nagasu. She trained that triple axel as a student.