Crosby was asked by Madden point blank who he preferred to play with when he was gearing up to return from the jaw injury. He said he would prefer Kunitz and Dupuis. I actually dug it up through the wonders of Twitter archives!
Listen here.
I can't give you a timestamp because that stupid player isn't showing one for me, but it's a few minutes in.
Madden: "Does it matter who you play with? You've had a lot of linemates during your time here, you play good with everybody, what's your preference?"
Crosby: "I think I'm the most comfortable with Duper and Kuni" because he's played with them the most. He then adds a bit more about how they've shown as a team that they can play with different combinations.
I don't think that was a totally unreasonable preference at that point; he was coming back from injury and going straight into the playoffs, and KCD had actually been a really good line in the regular season up until that injury. And I don't think that interview proves that when the going got tough and KCD needed broken up that Crosby dug his heels in, because after stating the preference he opened it up a little. But yeah, this is where that notion of Crosby preferring KCD comes from, not Bylsma.