Yeah it's a bizarre claim. I've described HN as a single, usually really good, subreddit before but it's absolutely not a replacement for the entire site.

Ironically Reddit also gives users way more control over their data than this place.

I'm not sure if you're being entirely serious but I disagree. HN is special because while it's a popular (relatively speaking) social media site, it's also run by a company that isn't in the social media business. YC is not concerned with how to make HN revenue generating, they just want to push people to where the real money is made for them: their startup accelerator.

With that said it's in YC's best interest to keep users happy, only change what is requested and generally keep the status quo. Unfortunately for a company like Reddit that is a social media site and has to make money with their social media product, keeping users happy at all costs is not in their best interest (though that has yet to be seen).