In the time of writing this answer, it is still not possible to use OAuth token for IMAP protocol targeting outlook.office365.com server.
As one of Microsoft person claimed, it is still work in progress. When it is done, they'll make an announcement.
Thay also claim, "We’re planning on adding OAuth support to both POP and IMAP in the next few months".
When Microsoft has implemented this in their side, we'll post an updated answer to this question.