I wrote a thing on Drouin recently on my nascent blog. I won't "self-advertise" and link it here but my thesis was that the Habs aren't necessarily worried about Drouin.
His contract is expiring after next year but ultimately you need some bodies to play hockey. We can't line-up with just AHLers.
Drouin is at his nadir with injures and reputation so it's better to hold onto him and see what happens with the MSL effect rather than try hard to get rid of him. He's 26, two years younger than Galchenyuk!, so who knows how he'll adapt.
I doubt we'd get a valuable return for him, so what's the use stressing about him? Is he stealing TOI from more worthy players? He's not even the worst contract on the team with Gallagher, Petry, Price, Armia, etc.