I’m pretty sure they meant reaching directly out to other tooling authors, rather than the general public

It's a public repo under a Facebook org; it's bound to be picked up on Reddit if it hasn't been already.

Personally, HN would be my go-to if I had a project to show and for which I was hoping for some high-quality collaboration.

If by 'reaching directly out' you mean contacting specific people, then it shouldn't be a public repo. Like I said, it's under a Facebook org, of course others will find it.

I don't think HN is general public