Eh, I think the utility of these threads is constrained. They grow to hundreds of comments quickly, and everyone has a 4-paragraph pitch. The keyword matching is difficult because people will say something like "REMOTE OK" ... "for the best candidates" or "for some positions". whoishiring.io usually gets a lot of stuff wrong. Most posts don't include salary information.
Once in a while, a candidate will make a reply about their experience with an employer, but it feels kind of rude to butt in like that, and I'm sure it would be discouraged/changed if it became a legit trend.
Like other HN threads, it locks after two weeks, so trying to check back in toward the end of the month when some of the fervor has died down doesn't really work.
As a candidate, you have the intimidation of competing with other HN users, who are generally very smart, tough competitors. And if you mention coming from HN, the employer will naturally inquire about your HN username, and then if you occasionally express controversial or unpopular views, as any interesting and/or honest person would, you have to worry about whether those are going to impact the process, especially if they veer political or social.
I think HN is outgrowing these threads. It's not a small community anymore.