I wonder how much of this is also based on the hotel's back office operations - do they / can their system actually go over the incoming guests and do the upgrades.

The other thing is also the hotels' internal pressure on making extra money. For example, I used to routinely get upgraded at the SF IC on Howard Street when I use my Chase Free Night. Last time (in 2022), they tried to upsell me - even a higher level room. Something must have changed post COVID so they are not as generous now.