There should be better laws to protect consumers in cases like this, or say when a chain hotel cancels a reservation during an eclipse. The booking site that takes the reservation should be legally responsible for re-accomodating guests in this situation.

Affected guests should be allowed to go on the Mariott site, rebook any similar hotel and do a chargeback for the new amount, minus any refund paid.

Furthermore, if I was told to vacated I wouldn't be bound by their deadline, but the checkout time posted on the door, or even longer if I had prepaid.

In most jurisdictions it is unlawful for a hotel to evict guests unless for safety reasons so it's not like they are going to call the police.