It details that in February 2022, the carrier will turn off its 3G network, which will make some phones lose the ability to make voice calls. Other customers even agreed that it's likely not a genuine email until someone eventually pointed to the support page that AT&T linked to through the "Learn more" button. The notice is poorly worded enough that an AT&T subscriber asked if it was a scam AT&T's forums, since they own a relatively recent Galaxy S10e.
Oh boy, free shipping on your new $1000 smartphone! Even a technically savvy person could be easily confused by this email, and it's easy to see how an elderly person might look at it and effectively get scared into purchasing a new phone immediately. The tone and language of the email make it sound like customers should buy a new phone via the carrier straight away: It advertises that AT&T makes "getting a new device online easy," detailing various free and fast shipping options.
Amid an economy-crushing pandemic, AT&T decided that now was a good time to send a scaremongering email to many of its customers, claiming that their phone "is not compatible with the new network and you need to replace it to continue receiving service." The email conveniently omits that this message is regarding a change that won't take place until February 2022, providing only a link that later calls out this change linked to the decommissioning of AT&T's legacy 3G network.