No one really knows how the waitlist system captures nights or how frequently it runs, but waitlists match without being manually booked by a CM. They just aren't booked on points without a CM.
You can have waitlists sitting that matched and have no idea unless you call or chat MS. Sometimes you can be calling about something else and MS will just say congrats, I see your waitlist matched, would you like me to book it for you? You can also call or chat just to ask if they matched. Or if you aren't obsessing over it you randomly get an email it was booked and it looks like a regular reservation was made. This doesn't mean it matched and was booked at the same time. It could have been sitting matched, but unbooked for days/weeks.