WFU will disable your accounts, including Google accounts, when you leave the University at the end of your term of employment.. As I understand it, the particular disable date is based on the dates in your letter of appointment and/or employment contract on file. If your contract says you are employed until June 30, then I would expect the account to be disabled on June 30 or July 1. Once the account is disabled, you can not access material in those accounts. Some time shortly after the account is disabled, it will be deleted permanently.
Here's what you need to do prior to leaving. Start early! This could take some time.