Yeah, from experience it typically goes like this:

Rooms department in the back office upgrades you to balance their inventory. They might pre-block you to a room that's currently occupied (potentially with one of those pesky globalists leaving at 4pm that only let the FD know at the last moment).

You arrive at the hotel at 5pm, housekeeping is swamped and hasn't cleaned the room, so they go back and find the first available room they can get you into now.

I personally prefer, especially when status/program is involved that includes an upgrade, that agents verbally confirm the room type and travel dates. We were trained to do that at Disney. Most agents however seem to just cut the keys and send you on your way hoping you won't notice.

Made that mistake once on 12/31 at the Grand Cypress and lost a Disney NYE Fireworks view that way.