If you have a note in Keep that has something in the vein of "movies", "TV" or something like that, Google can now help you out by autocompleting the show or film title that you might be trying to add to your watch-later list. If you use Google Keep, you've probably seen the autocomplete feature in action for various tasks, or for adding items to your shopping list, but being able to autocomplete show and movie titles can be plenty helpful.
One odd issue is that you may have some trouble if the title of your note isn't totally right. Apparently, "movies" will work, but "movie" might not. Similarly, "TV shows" will work, but "TV series" might not. We're hoping Google sorts out these issues, but a bit of trying will certainly get it working.
source: Android Police