Currently, Archive Manager can archive Office 365 information when an On Premise Exchange Journal Mailbox is specified in Archive Manager.
A Journal rule is setup in Office 365 to forward the mail items to the on-premise Journal Mailbox. Archive Manager then scans the journal mailbox and archives each item appropriately.
In a possible future release, having an on-premise Journal Mailbox may not be required as Archive Manager would be designed connect directly to Office 365 and Archive the items.
Enhancement Request ID TF00193439 is open with the Development team and could be implemented in a future. If you wish to request a status of this Enhancement request please feel free to do so at any time.
Thank you,
Dave