If you cancel your workspace account, then the individual user accounts will still have access to non-workspace services [0], which importantly includes Google Play and all access to your purchases will be retained. Any other google services which aren't core apps will also work as normal.
Any former GFYD account becomes a semi-account with access to a subset of google services but not all. Since the account exists, it cannot be used to sign up for a free personal account, and you can never use google docs or have google docs shared with any former GFYD account.
Overall, this is a better resolution than I'd feared, but it seems ridiculous that being a loyal google customer for over 15 years leaves you disadvantaged.
[0] Core workspace apps: Calendar, Currently, Drive & Docs, Gmail, Chat, Meet, Groups for business, Jamboard, Keep, Sites, Tasks