> a user who has passed some threshold of number of edits to a single article (say 100) would be automatic grounds to block the user from further edits to the article

This would not be without precedent. I was an active Wikipedia editor in 2004-2006, and I recall an editor (later admin), who was otherwise a great contributor and a positive force in the project, who had a seemingly unhealthy obsession with singer Ashlee Simpson. After multiple arbitration proceedings, he was restricted from editing her Wikipedia entry under threat of 24-hour bans for each edit.

Here is the notice of the final arbitration ruling [1], mentioning the prolonged history of the case.

To be fair, it was a different time back then. Not sure if a ruling like that could or would be done today.

[1] https://en.wikipedia.org/wiki/Wikipedia:Wikipedia_Signpost/2...