[mrweasel]

> I bet the vast majority of them (like me) switched to the paid version

I don't think that's true. Everyone I know who used custom domains with Gmail migrated away. No one paid, Google priced it just high enough that people could justify spending the time migrating.

There might have been a solution where you could keep the custom domain, if you used it for email only, but the messaging was really confusing, and many had already migrated away at that point. There may also have been issues if you hosted email for others. In my case I had my own email and that of a few family members, it wasn't clear that I could keep all the email account, or just my own. In the end I think many didn't want to deal with Google after this and just moved their domains.