Whether stated or not, this is basically true of all professional VCs. That doesn't mean it's right or wrong, only that if you want to get funded, figure out a way to get an introfiction. It's far from impossible, even starting from nothing, and it's much easier than 10 years ago when far fewer VCs wrote/tweeted/commented in public.

By late stage for us, I was thinking that you still also have YC for the earliest stage and it's still the best way in the world to "cold pitch" someone but still have a chance to get funded and identified with no existing connections. It worked that way for me, anyway.