Why did Google coexistence stop working after the MigrationWiz project was deleted?
If the MigrationWiz project associated with the token used for Google coexistence is deleted, coexistence will stop working.
We recommend that a separate MigrationWiz project be configured that will only be used for the configuration of Google coexistence. This project will remain empty as a Google-Office 365 Coexistence placeholder. No users should be moved into it during the entire coexistence.