Recent randomized example so take it for what it is worth:
1) Booked the Palazzo las vegas with Virtuoso on a Thursday night. did not get an upgrade, don't even technically think I got the floor I was supposed to, but essentially a free upgrade to the club lounge which is automatic and did get a late-checkout to 1pm which is all I asked for
2) Next day, stayed at the Wynn under an FHR booking. Got an upgrade to a strip view and got a 2:30pm early check-in (did not ask for late check-out).