Just migrate my old rMBP 2012 to new MBP 2018 with Migration Assistant. Everything seems as good as old one, but Office365 is not activated. When activating Office apps, it always fails, reporting unknown error 0xD0000FFFE.
Apparently, it is related to some migrated existing license. After Googling, some solutions like deleting folders under ~/Library/Group Container will also remove your Outlook inbox folders, which is surely unacceptable. This post has the correct official software to remove existing license and then re-activate Office365 will succeed happily.