I did not get it either on AT&T.. I never got the last update either to 4.3..Had to do it manually on HTC site. Calling does not help. They have no idea..
It's not on their website yet. Usually takes a month or 2 after the OTA is released. I did it for 4.3 jelly bean. And forwarding the date in calendar did nothing for me..
I had no problems getting it a free days ago. Went into settings and clicked on AT&T Software Updates and it started to download right away. It isn't a huge update, so I wouldn't worry to much about it. Just keep checking.