what if

Avs decline, for the 100th time they aren’t trading anyone before the XD, they can’t and it doesn’t help them

maybe, maybe not.
Look Avs gonna have a lot of cap on that blueline. Too much they just got to many players back there. Someone is gonna go.
Even if they don't trade him, Maybe he's the piece coming back from Seattle at this point.
The only thing COL can do is make a deal. But that doesn't really help them as the blueline is packed with bigger contracts. You got Makar gonna get paid, Toews, Girard you got Byram coming in and Timmins.
They are packed on the LD, someone's gonna get moved. They can't protect forwards as they are already at 4 and 4 and got no room. It just looks like a good move.

Trading anyone before the XD means they lose another good player

So what’s worse losing graves only or losing donskoi and trading away graves for nothing that helps their roster

So now they created 2 holes in their roster. Like I said they are not moving anyone before the XD, plus there are exposure requirements and they need graves for that

Avs are going 7-3-1, not 4-4

I don't see this as true. Some loses are not as bad as others. I also see them going 4-4. I mean if they took Jost and a 2nd I don't think COL cares. Which is better than, say losing anyone you can't protect. So you aren't losing 2 guys, you are gaining the ability to control your loses.
I see them protecting Donskoi for the record.
COL is deep, and truth is, it might be they give up the pick they get back on moving Graves to make sure they lose the guy they want as opposed to just letting SEA have at it and pick a guy they would have rather kept but couldn't. The pick plus the guy they take isn't nearly as bad as them just going at it. .Or as I said, maybe he goes to Seattle, the penguins keep their pick, and Seattle sends him over to the penguins.
As I said at the beginning of the post, this is a rough idea.
But I'm not sure I agree with you that trading him doesn't happen. It might be the equivalent of what you have to do anyway. Pay something + lose something, to make sure you don't lose the guy's you want to keep. It's not a clean cut, lose 1 or lose 2 situation for COL. You are most likely losing 2 of something. It's just what two and how do you control that loss.

0 chance hextall trades his second this year. they need to slowly start building for the future