> This kind of selection bias applies to everything, e.g. you don't see the news stories media doesn't report on.

Traditional media like TV or newspaper or a YouTube channel, agreed. On some media you (partly) do tho ie. they allow more transparency.

I remember (back in 2002 or so, not sure nowadays) on Indymedia they had an open publishing method. All declined articles were in a recycle bin. Admitted ones were in the newswire, starred ones in middle.

HN has a "new" queue. Everything from there which does not get enough points, does not get reported, as it does not reach the front page (nor page 2).

Either way it is a shitload of work to go through this manually, though.