Yes, it's a thing. I worked in hotels. If Housekeeping entered a checked-in room and saw that it was completely untouched, they reported it to the Front Desk. The Front Desk would have someone check the lock to see if it was used. If not, the reservation was marked as a no-show and checked out (if it was a multi-night reservation).

I can't provide any evidence that we did this because keeping check lists or policy manuals that discuss that procedure would be weird. It's also proprietary information.

But, you don't have to believe me. I don't really care one way or another.