Everyone I know who works in security has seen Some Stuff. But I've never seen a website that told users you must remove two-factor authentication.
@mshelton Only phone number (i.e., Text Message) 2FA of the three provided is being taken away, the one that SIM shenanigans can make useless. Why, if it is a problem, T-Blue users get to use it is baffling, but there you are.