IMO perfect is the enemy of good here. If your personal email account you use for literally everything is firstname.lastname@mailprovider then you're already in the same situation. This isn't any worse, but it is strictly better.

You can always create a new identity, I don't think anything has changed there. If you don't want your new identity connected to your old identity, then don't.

The right to be forgotten is whole separate problem. The only hope here, really, is that entropy takes care of it for you. I don't see how a chain of trust system can fundamentally be compatible with the right to be forgotten unless you relax the rules a bit.