Amazon's hired people remotely. People have moved away from Amazon offices and bought homes. Etc. Perhaps some of that is covered by a small number of exceptions but it wouldn't surprise me if a substantial number end up leaving or getting fired.
2.5 months also isn't very much time to relocate if necessary. Amazon could easily have given a MUCH longer transition period. It's quite cruel to workers, many of whom have planned their medium/long term around remote work.
Even if there are a few exceptions, the whole tone of the letter is "Don't count on it." He could easily have written: "If you don't live within commuting distance of an Amazon office, your manager will work with you over the next X months to develop a RTO plan for you."
I don't think they hired people fully remote. My 'remote offer' was still tied to chicago office, with expectation that i'll be back in office at some point.
I got hired last year btw
EDIT: Looking at PhoneTool, our "office" location is stated as "Virtual Office - <State>". So "Virtual Office - Texas" for example for someone hired fully remote in Texas.