Honestly, i find this really unacceptable.
I work heavily with search based on tags and so this flaw annoys me everytime i use evernote.
You wrote that search results that reflect changed tags are a matter of hours. Not here, its a matter of days!
Assumed i have chosen to select a filter including all notes with tag X that returns a resulting note list with one note with tag X. If i then remove that tag from that note, the resulting list does not remove that note. But that would be a desired behavior.
In my opinion this would't be a benefiacial search behavior. I have many code snippets stored in my notes and therefore many Strings like <class>.<subclass>.<method>. Therefore i would never find my note, when i look for <method>.
I created a note "Test" with a single string in it "abcd.efgh.ijkl".
If i search for abcd, the search returns this note. If i search for efgh, the search returns nothing.