Hey, sorry for being MIA: had my first interview this week and was swamped!
My two cents: More importantly, I think that UNC is considered a safety net for many, many applicants. It's an "easy" first interview, is a solid umbrella program, and has a reasonable priority deadline. I got my UNC rejection on Friday along with everyone else. I would argue that UMich has a better Neuroscience program than UNC (Huda Akil vs. Tom Kash,) but it depends on your specific research interests within the field. I'm surprised that PIBS only offered 100 interviews... wow! Thanks for providing that insight- I'm also hoping to get a better idea of the applicant pool size vs. interviews offered during my interview weekends.
I think that more students applied this year because a) they had nothing to lose and b) GRE requirements were dropped by more institutions than the last cycle. Plus: there is a higher focus on DEI and recruitment of minorities. That alone spikes the applicant pool a decent amount, especially when you consider first-gen and non-traditional applicants (like myself). I'm still amazed that I got at least one interview. The competition is berserk, and we need to keep uplifting and supporting each other. It's so competitive, I can't wrap my head around it. My interview this week only had 14 students!