Steps to convert user from AD sync to Cloud in O365
delete user in ad and sync. restore the user in O365 from bin, and now the user will be a cloud user. run the following command for user maikelb@domain.nl : Set-MSOLUser -UserPrincipalName maikelb@domain.nl -ImmutableID “$null” Now the user will stay in O365 after a new sync from Ad to O365