Originally Posted by ethernal

Right or wrong, there is some nuance here based on the length of stay. There is a difference between "Available" in the sense that you could book a room versus "Available" in the sense that they don't believe they can sell the room. In a hypothetical situation, if you have a 5-night stay and there is only 1 suite available for the length of booking, I should not reasonably expect to get that upgrade. Revenue management would say that the room could likely be sold for at least one night over the duration of the stay.

Obviously the issue here is that if you don't have a hard-and-fast rule about guaranteeing an upgrade if a room is available for booking (which is NOT what the terms and conditions say - they say "available" and then do not define "available" anywhere in the T&Cs leaving the definition up to the property) is that hotels then have complete carte blanche to say "well, there is a 0.001% chance that all 47 of our suites will get booked during a portion of your stay, therefore they are not available."