It is partly fixed.  When I go to  the Watch Later page and click on a video from the list, the bar at the bottom of the page does not display. 

However, the issue with videos added to Watch Later not immediately going to the Watch Later list is fixed.

 

Also, with the new homepage, the Watch Later notification only displays under the "All activity" tab and not "Subscriptions uploads".  It is inconvenient for users who want their Subscriptions upload tab to be the default tab.