Crawled properties from on-premises farms
Crawled properties from on-premises farms should be added to O365 in Hybrid search (cloud index) scenario.
David Lozzi commented
they are! You have to log into O365 with the service account crawling the content on-prem. It's redic. I created a new uservoice for this issue https://sharepoint.uservoice.com/forums/282887-sharepoint-hybrid-or-migration-to-office365/suggestions/31650862-allow-admins-to-see-all-hybrid-search-properties