Improved user logout notification ( #23295 ) is now in core, and its UI has been tweaked to directly show the login box, rather than prompting first:
There’s been discussion as to whether it’s better not to block the user’s access to the editor/current page when we detect that you no longer have a login token, since it could stop a user while they’re in the middle of a sentence. Any opinions either way? Feel free to comment either here or on #23295.
A simple way to test the above is by removing your login cookie while working in WordPress (Firebug works well).
On local autosaves, there was a decision to pivot from the previous UX posted here, and instead integrate with the new revisions model. This code is still being worked on.
In the land of post locks, @azaozz posted a patch on #23697, that shows a dialog either when you visit a locked post, or when your post becomes locked. If you are visiting an already locked post, you have the option to break the lock. This is still in need of UX/UI love, but looks like this currently:
Finally, a patch on #23665 allows for one autosave per user per post, rather than per post, to let us keep an autosave from before you lost a lock. Testing on this, and the rest of the above welcome!