One of the kids that was accepted to all 8 ivies last year chose a full ride with Alabama honors program instead, as discussed at http://www.businessinsider.com/ronald-nelson-turned-down-every-ivy-league-school-for-university-of-alabama-2015-5 . Of course this doesn’t happen often, as students who favor Alabama over Harvard generally aren’t going apply to spend a lot of time and money applying to Harvard as a backup in case Alabama rejects them. Instead they’ll skip the Harvard application altogether. Furthermore the schools are in different sections of the country. I’d expect the main exceptions to relate to financial surprises, such as getting a competitive Alabama scholarship or worse FA than expected at Harvard.