How so ? I can't recall any major free speech issues on HN. Being downvoted and having your comment hidden is not exactly something HN can do much about, seeing that it is up to the users.
The quality remains relatively high on HN though. I'm pretty sure it's the only website I've used consistently (ie almost every day) for ten years.
I know some political posts (and definitely trash/advertising) get cut and not everything (as defined by "free speech") gets through, but on a personal level for me (and I'm sure many others) I think the moderation works.
I like HN. I am not saying it is heavily moderated to make them stop moderating it.
But the fact is, it is what it is precisely because a lot effort goes into moderating it. Acting like HN it's some kind of free speech place is absurd.
Claiming that HN is good and then going into outrage because another site applied significantly looser restrictions is dishonest. For that matter, trying to pretend the Donald or incels subs were merely normal subs merely discussing conservative policies is outright lie.