I seem to remember reading that they changed the login mechanism, (when using a password), so that it operates in a secure environment inaccessible to the user thus the normal methods, (Ophcrack, John the Ripper, etc), wouldn't work and that you could really only reset passwords under Windows 10.
Note, this is my understanding/interpretation, quite possibly wrong, based on a half remembered article read over a year ago.
f0dder would definitely know.
In the meantime, this might be what I'm thinking of:
Windows 10: Virtualization-based security