After interviews, everyone gets ranked, so for my year (this was the weeks before PHX was approved), the first 48 applicants in the ranking received offers the Monday after interviews. This year, I'd think more applicants will get offers on the first day because PHX is up and running.
Perhaps the top waitlist students hear back that day too?
Since there are more interviews this year, I have no idea if they'll be as quick with their offers, but hopefully so!
Reading over these recent posts, sounds like my ~200 number was off by 50... 250 interviews, wow! Since interviews will also take place in PHX (not the case last year), I can see how this is doable.
And yes, whether or not you get any "ridiculous" questions is totally luck of the draw... my luck gave my 2 interviewers who chose to be more "creative" in their questioning, but most of my classmates had interviews that were not random at all.... just want y'all to be prepared just in case! Good luck!!!