He put up 30 points in a season when the Canadiens were terrible and he was getting inflated ice time cause the roster was garbage and riddled with injuries. This year they're better and he's showing his true value, he's an AHL player/occasional 4th line plug.
Simply put Janmark is a better and more valuable player then Hudon and isn't worth sacrificing for that move up in draft picks which aren't likely to be of any on ice value in 2-3 years at best.

When Hudon plays, it's on the 3rd line and PP because he is too talented to be playing 9-10 minutes a night. He has talent, he just doesn't play well enough defensively (which Julien demands), hence why he is a Healthy scratch.

@BurgerBoss @KSIxSKULLS

Dallas would trade Janmark since it’s rumored that he’s being dangled, per Elliotte Friedman.
Dallas would want Hudon because he can provide offense on an offensively starved team. (Other than the first line.)

Montreal would want Janmark because he is a more defensively minded player that can play in the bottom-6 and be an upgrade on Chaput for this year. Next year he could play wing.

I wouldn't call Janmark a defense-minded player. His biggest strength is his speed. But he doesn't really bring too much to defense.

Edmonton literally said on Wednesday that they aren’t trading any of their picks unless it gets them a high end player.