I was confused by the terminology between Meta, Oculus and Facebook accounts, and which was an upgrade of which.
When confronted by the upgrade (I was actually trying to do something else, which required upgrading the account to Meta, which required upgrading the software) I tried the path of least resistance, which was just "log in with your email". I didn't remember if this was how I always logged in, and honestly this is a gaming gadget which receives far less atention than my laptop or mobile -- I just figured whatever I chose would be harmless. Turns out this wasn't right, and then the oficial docs warn that choosing the wrong option may result in creating an empty new account without any apps/games, which will require deleting it before proceeding, which may take up to 90 days.
I freaked out, tried logging in, it didn't work, freaked out some more and one of the random things I tried (I forget which) worked and I suddenly had all my stuff again.
Noteworthy here: I'm tech savvy, this shouldn't require freaking out, and in fact it should be smooth sailing, something like "click here to upgrade, done, you're ready to go".