On the basis of elite status at Nordic Choice hotels, I’ve had complimentary late checkout honored per the program terms, and that’s even with the 6pm checkout. I’ve been asked to clear the suites early a couple of times, but always with an offer to be moved to a different room if I needed it to have a place until the late checkout time.

I’ve also generally had Hyatt properties honor this kind of status benefit without issue, with some rare exceptions.

Marriott is a different beast, but typically this is one benefit that Marriott/Starwood were generally very good about abiding to with regard to program terms — at least pre-2020.