In Theatre View, in my Unwatched View, episodes disappear as soon as I have watched them. The View is immediately updated.
In Standard View changing tags does not immediately update the View. Not until you click around to force a refresh, or click refresh. This is normal. It is sort of my preferred approach, unless MC learns to read my mind.
For example, I was changing Genres on some files this morning, where some files had the Genre "Drum'n'Base" while others had "Drum'n'Bass". Of course it should be "Drum'n'Bass", so I searched on "Drum'n'Base" and edited the Genre tag in place using a Panes View. The files all stayed visible in the View until I had finished editing, which is what I wanted so that I could see the change. If the View refreshed as soon as I changed the Genre, the edited files would have disappeared from the View immediately, as they no longer matched the search criteria. This would be bad, as I often make mistakes when using Panes View tagging. It is tricky when you don't do it often!
So, as far as I know, it is the way Standard View Views have been working for a long time.
In your specific contrived example it may make a difference if you had "Filter in both directions" turned on in the View definition, but I'm not sure on that. I tend not to see that feature, but it is handy for Panes Views, I believe.