This is actually a rather silly statement, considering that DMC games have a vast amount of replayability outside of just playing for the story. The gameplay itself is why people still make combo videos for ten year old games
I think Vash and Judge meant new story content would be something that could appeal to casuals more than the gameplay changes like 60fps/lock-on which is true-ish and i think people are getting ahead of themselves with DMC4 as they think Vergil's inclusion would lead to new story content (maybe/maybe not).
Basically I'm not agreeing with Vash, in fact I think he makes some incorrect assumptions. Yet I agree with some of what he said. I think a lot of players will never see Gods Must Die mode, yet alone buy the game for a super hard mode, when they barely finished it at Nephilm mode.
Don't get me wrong I hope a lot of players pick up DmC so they can see how good it is, but I agree where Vash was coming from with that remark.
That works for DMC4 SE as well. A lot of people seem to have in their imagination that DMC4 SE will contain double the content DMC4 had. Since apparently DMC4's development was cut in half. They expect half the game will be remade or made for the sole purpose of making DMC4 feel like complete game. Theres no proof that Capcom intended to make DMC4's content or lenght anymore substantial than it actually was.