ODM O365 to O365 migration and Azure Information Protection Encrypted emails

I have a support ticket in about this, and I'm wondering if anybody has had any real world experience with ODM and Azure Information Protection Encrypted emails in O365 to O365 tenant migration? 

Support are being non-committal, saying to test first. Which is difficult because it can't only be tested after Domain cut-over. I have the required M365 licencing for both sides for AIP encryption. I'm just unsure if the Migrated user will definitely be able to access the Encrypted emails they had access to once migrated to the new mailbox.

If there is any documentation I've missed, I'd be grateful for a link also.