saw a couple schools already started pulling from the WL (even those that usually don't start until may 1). did this happen last year too or is it unique to this year?
Yes. It happens every year. For the schools in particular you were thinking about, you should browse their past application threads e.g. 2018-2019 year. People usually say when they’re coming off the waitlist. If you do not have an acceptance, start prepping like you have to reapply if you think you’ve improved your application.