Thank you. That gives me some hope.
It indeed happened very recently as I only saw it today.
It's for a flight later today, so I checked in online and now I'm told that the passengers are added to gate upgrade list.

Slightly longer story: the record locator was initially for a different flight which was upgraded, but it was cancelled due to weather yesterday. So they rebooked me and reapplied swu on this new flight.

Since the flight is for later today, I called in EXP line and the agent said it's not upgraded yet and she has no idea about what I see on aa.com. She even tried to check the trip on aa.com herself but couldn't see what I saw (maybe because I logged in when I checked).

I'll post here what happens at the end.