[Znuff]

> I understand you just lose all your Google Play purchases and need to re-purchase any apps or subscriptions you want to keep. I'm assuming this will basically require an Android phone factory reset and to be setup fresh with a "new" Google account for the old email address? Is this the case?

You understand wrong.

You do not lose access to your purchases. You will still have a Google Account (with your own custom domain), it's just that after the conversion from G-Suite Legacy to Workspace, if you stop paying it it will not allow you to access the "core" products (Gmail, Drive, Calendar, whatever).

Nothing stops you from moving your e-mail somewhere else but still keeping the Google Account with that domain.