Following the release of Android Oreo for the LG G6 on Verizon and Sprint, AT&T has now begun rolling out the update to the phone on their network. The carrier hasn’t updated their support page for the phone just yet but it should be the same build that hit the other two carriers.
Assuming that is the case, you can expect an update of around 1.8GB in size so it is certainly one you will want to download while you are on WiFi. You’ll also need at least 80% battery remaining on your G6 before you can install the update. Along with all the Android Oreo goodies that come with the update, you will be getting the May 2018 Android Security Update patch for your G6 too.
The unknown, at least until AT&T updates the release notes, is what carrier specific updates are coming on board. The carrier tends to update their own built-in apps with these types of updates so that is likely going to be the case for this update too.
If you have a LG G6 you can check for the update by going to Settings>Software Update. All indications are that AT&T just now released the Oreo update so it could take several days before it gets to everyone. The good news is it is coming to you, it just a matter of when.