stillalex, i would be really surprised if removing a 'mandatory' would have any impact. while i don't know all the details of the nt-code-base in oak, i can assure you that i am not aware of any regression/ticket/complain associated with dropping the 'mandatory' from the "rep:password" property quite some years ago. so +1 for the proposed fix. if you don't mind, i will also link it to the corresponding issue that made us aware of the problem.
Adding 1.10 version before 1.10.0 release