quote near end for the many people who won't read the thread:

    - This change makes it so that `autocomplete=off` does not stop the Password Manager from working. Normal form autofill can be disabled as usual.
    - The password manager *always* prompts if it wants to save a password. Passwords are not saved without permission from the user.
    - We are the third browser to implement this change, after IE and Chrome.

More clarification: password type input elements already never autofill/autocomplete like other input elements do. autocomplete=off on password type input elements just makes password managers not work (until this change). Other input elements still honor autocomplete=off.