Any items designated with a 'Starred' or 'Important' property that was set from an email client that supports a 'High Importance' designation have unique behaviors when being migrated from Google to Exchange.
Starred Items: Items marked as 'Starred' will have a red flag designation in the destination mailbox, indicating that this item was marked for follow-up.
Gsuite IMAP Endpoint - Important Items: Items marked as 'Important' will have no discernible markings within the destination mailbox. These items will display as a normal mail item.
Gsuite API Endpoint - Important Items: Items marked as 'Important' will be marked with High Importance in the destination.
When migrating items from Google, if there are any tags associated with the item, those tags will supersede any other labels that may be associated with it.