Read those threads more carefully. The first only claims there are ways to boost OR identify YC alum posts (pg clarifies). The second implies you get a "boost" but does not say that HN itself gives that boost.
As someone who tangentially interacted with YC founders, I can confirm that HN does not inherently boost posts, but HN does identify YC alum posts to other YC alums, which is probably the source of the "boost". In fact, HN on several occasions has penalized YC alum posts (upvote ring detection).
Saying YC employees have boosted stats implies that HN boosts those stats inherently. But that's not true. What happens is the same as what happens when people post their HN submissions on twitter/Facebook and tell all their friends about their HN post.
I guess it depends on if you think that things that boost behaviours inherently are included or if only software counts. I see it more akin to if some users submissions were automatically tweeted whereas others had to copy and paste.
I didnt realise they had taken out the alerts on their dashboards that led to YC members being picked up by the vote ring detection.
