In additional to Karthik's points above, I would like to see a scheduled date in which waitlists will be cleared and an actual cutoff date for rookie team registration (likely both of those things would be the same date). This would give teams/parents/schools a definite date that they will know one way or the other, and give event coordinators a date when they can stop holding spots for rookies that may or may not show up (as holding those spots is at the expense of veteran teams that are left in limbo wondering).
Fortunately my team isn't on a waitlist this year (only because a number of factors worked out in our favor to make that possible),
but I estimate just in Michigan there are 138 teams on a waitlist without any clear idea of when they will be accepted or declined or reassigned. At least with districts waitlisted teams know they will get into an event somewhere, even if they don't know when or where, so it's not as bad here as other areas (but still frustrating for team leaders).