I went to POP last year and am now going to be attending Pomona in 2021 because I deferred enrollment. If you’re accepted to POP, it’s not so much that your chances increase, but it just means that you are already the kind of student they’re looking for. When we were there they mentioned how the acceptance rate for POP was similar to the acceptance rate of Pomona itself, so all the POP attendees already made it through a selective process. The acceptance rate for POP students in the year before mine was 80%.