So, I got on with AT&T Customer Service, just to see what they would say about these updates for the L920. After I got done explaining to this person that no, I didn't want the Amber Alerts, and yes, there really are updates available for my Lumia 920, this is the response I got:
ATT CS Tech: Oh i see, yes you are correct. Yes it has already started Joe.
Joe: So you're telling me right now that AT&T has started to release the Nokia Amber and Microsoft GDR2 updates to its Lumia 920 customers in the United States. Is that what you're saying?
ATT CS Tech: I do have friends that have got those updates yes, that's correct
Joe: And your friends are on AT&T, in the United States, and they received these updates from AT&T? When did this process start?
ATT CS Tech: Yes that's correct I am not sure when it started but they got updated last weekend.
ATT CS Tech: They got a text that it was available. Connected to my Wi-Fi and updated the device.
Joe: Okay, I will watch for this. I am going to be copying this conversation, removing your name, and posting it online, so that other AT&T customers that are Windows Phone users can see what I am being told by AT&T.
ATT CS Tech: Ok great, sounds like a plan. Thank you for your patience and understanding. I hope all my customer interactions today are with awesome people like you, thanks again. J What else can I help with today?
Joe: that is all, thank you
Take it for what it's worth, but I thought you would find it interesting reading.