We have a similar scenario in our solution. That would be awesome to have Graph API to support accessing in-place archive mailboxes. Hope in the next API release this feature will be included.
Agreed with the post and subsequent comment. The inability to access Archived Mailboxes is a huge problem. The majority of a user's email many times resides in the Archive Mailbox, The inability to access those emails forced us to use the EWS API which we hear is on the road to deprecation. Graph needs to support functionality that has been in the EWS API for years.
