While this is the expected norm for most 15 year olds, the under 17 year old undergrad classmates I knew were treated no differently by their respective parents than the more typical 17-22 year old undergrads regarding living far away in dorms with other undergrads.
And they carried themselves so much like mature 18-22 year olds that one would have a hard time guessing they were under 17 with the possible exception of being “young looking” unless they trusted you enough to tell and show you their ID as both of them did.