Email is not a good second authentication factor anyway. I have 6 u2f tokens on my high priority digital accounts, as well as printed recovery codes in several places. Only 1-2 tokens ever actually travel with me, the others are kept safely in different locations.

Given that most people are cracked wide open if their password manager is compromised, I do feel it's sensible for a password manager to insist on 2FA, but the email chicken and egg problem is a concern for those migrating, and hopefully they backed up their recovery codes.