HN not only shadow bans commenters, they will also poison placement of comments (algorythmically) in a sub thread based on who writes the comment.
Lots of software affects both story and comment rankings. "Poison" is a rather tendentious way to describe that. HN's goal is high quality in all things, to the extent it's possible. That doesn't just happen by default; systems are necessary, and it gets harder as numbers grow.
NB...The words in my signature didn't come from a random sampling of the dictionary...they were from a screen grab of HN moderation tools...
On the topic of changing subjects, no not really.
Those words are outrageously inflamatory.
We're happy to answer good-faith questions about HN moderation, but this seems like trying to stir up drama.