You're right, I didn't explain in much detail the motivation that will push websites to start requiring the remote attestation flag to be set. I will try to cover that in a future article.
But as for how it could "catch" you: if you use FOSS devices that are unattestable (as is the case for the LineageOS phone and Linux laptop I exclusively use), you may one day find you can't use many websites.
But as for how it could "catch" you: if you use FOSS devices that are unattestable (as is the case for the LineageOS phone and Linux laptop I exclusively use), you may one day find you can't use many websites.