Purchases won't go anywhere. You will be forced to the new plan, and then when you fail to pay you will lose access to the mail and the workspace apps (so will lose Docs Sheets, etc access), but the account remains a valid google account indefinitely.
From the FAQ:
> If my G Suite legacy free edition account is suspended, what happens to my additional Google services and paid content after July 1, 2022?
> In account suspension, you won't lose access to other Google services, including YouTube, Google Photos, and Google Play, nor paid content, including YouTube and Play Store purchases.
> You'll also be able to sign in to your Google apps (such as YouTube) and third-party sites with your G Suite legacy edition email address. You won’t be able to receive or send email, including authenticating password resets via email. Without access to Gmail in the suspendedstate, we recommend you use a different email provider to send and receive email messages, including changing logins and authenticating new passwords.
What seems to be weirdly missing is the option to convert to normal non-gmail google account, which is what most individuals or families willing to migrate to a different email host would want. If they offered that, it would allow keeping access to gdocs et al, and you would really only be losing mail hosting and the ability to administer other accounts.