Install Office on new pc. Was installed on old pc.

[BlueSpruce]

I set up his accounts again. I had to anyway, even if I had access to his old pst files, which I did, as the old disk was fine. That is now his backup disk and he can move any old data at his leisure.
It was really annoying though, as imagine if I was telling him how to do it over the phone, and it was not happening. You would think he was doing something incorrectly?

My 2019 Outlook respects the default choice made.

You can remote into his new box and also create an offline OST file that syncs with the mail server.