[Telaneo]

Not add 2fa automatically, but instead prompt with options to add it.

This probably doesn't comply with the relevant recommendations, but cutting a user of from their email is worse in my opinion.

[deepsun]

I'm sure Google prompted author for years begging to turn the 2FA on, as well as warning that they will enforce it on day X. Author ignored them all.

[mulmen]

Why is 2FA so critical it’s worth proactively breaking the user? What’s the even more bad thing that would (not could) happen to the user if 2FA was not enabled?

[Telaneo]

That doesn't make forcing it any less wrong.