I'm looking at that thread now, and it doesn't look like the first student was accepted off of the HPWL until May 5th? Wasn't traffic day also April 30th last year?
Edit: Now I'm looking at the 2017-2018 thread, and that year, it does look like students were starting to get accepted as early as April 30th. Regardless, this year is definitely an abnormal one.
Edit #2: Alright well it's 2 AM and what else is a neurotic premed supposed to at 2 AM other than look at previous years' SDN threads? In 2016-2017, the first student didn't post a HPWL acceptance until May 9th- that year, 6 people posted on SDN that they got in off the waitlist.
I've now gone back all the way to the 2014-2015 post on SDN. Every year from then until now, there have been 6+ people posting that they got off the waitlist. In 2014-2015, they overbooked and it looks like they took zero applicants off of the HPWL. However, it looks like the language that they used was very different. That year, applicants were flat out told that they should expect zero waitlist movement while this year, it seems like the admissions office does expect there to be at least a little bit. But I'm definitely just reading into everything too much and trying to find significance where there is none.
Here's the post if you guys are interested in becoming just as neurotic as I am:
2014-2015 Rutgers University - Robert Wood Johnson Application Thread