There is no such thing as a “finished state”, when it comes to notes in a Zettelkasten.
Notes in a Zettelkasten are in constant evolution. They change along with one’s mind: they continually adapt to new knowledge and new insights. Just as one can never stop learning and creating insight, notes in a Zettelkasten can never reach a finished state.
This goes hand in hand with the idea that Perfectionism Has No Place in a Zettelkasten. A note being “perfect” would imply there’s a “finished” or “can no longer be improved” state it could be in.