I'm having the same issue. Not only does the title bar no longer say "Saved" or "Last saved by user," but the little blue spinny circle no longer even appears for a second when clicking the Save icon. It's like I save and nothing happens, whether I click the icon or hit Ctrl+S. The only way to confirm the document is saved is by checking the "Date modified" column in my folder and making sure the time equals the current time. This (A) breaks my concentration while writing (B) and fails to fully reassure me the document is saved, in the absence of those other indications. It's extremely parannoying (I know that's not a word, but it should be!) and needs to be put back the way the way it was.
EDIT: I just checked Excel and it still shows "Saved to PC" in the title bar after saving changes. The problem is only with Word.
EDIT2: Someone just suggested I repair Office through Settings, which I did, but this didn't fix the problem (even after restarting).