Same here! I'm in Rhode Island, and I also have a Note 9 with AT&T, and I've been checking for updates maybe once or twice a week, for the last month. It didn't update on its own. I happened to check for one around the same time you did, it was about 7pm eastern time!
From what I read online it's for unlocked phones. Not phones that are carrier locked. And good luck for us TMobile users they don't even pop up on the schedule.