If COL had no other option but to trade with ANA, and Vatanen + 2nd was the best offer -- they would not retain salary. They could play Duchene on defence and be better off without the trade
The GMs that value a D like Vatanen come out and deal early. The rest are stingy and stupid enough to clearly set their team up to fall on its face.
Might have to wait until the trade deadline to find an eager GM again, when cap space has been banked and uncertainty about their team's chances have declined.

As for COL and Duchene, I think we're all idiots for waiting and dreaming because no outsider will see the conclusion coming. More like Stastny than O'Reilly, more like Kesler than Nash.

I agree. We would need to give up more than vats for Duchene (maybe a B prospect like Jones/Comtois/Morand?), and I would like to keep our second, seeing that we do well in the second round. Maybe a distant 1st, then the salary retain can stay? What do you think?

I'm sure a deal where salary is retained is possible, it'll just hurt ANA to make the deal in some way that almost certainly sacrifices future playoff appearances in exchange for a better chance at the cup in the next 2 seasons.

Honestly, I think Duchene will pick his destination and COL will get a lot less than they would have 1 or 2 years ago.
Teams will demand the trade be contingent on Duchene signing an extension, given he is UFA in 2 years.
Duchene's agent has been unhappy out in public, cooperation is gone because trust in Sakic making a deal asap is gone.
Duchene will want to avoid repeating his frustrating time in COL and really limit the teams he'd go to.

If Sakic is GM, most likely Duchene just plays out his final 2 years and leaves like Stastny.
If ownership fires Sakic, or threatens to fire him and have his replacement do the deal, it will be the best current offer by the teams Duchene names.
Duchene will only be a top 6 in ANA as a winger, and it's doubtful they have cap space to sign him in 2 years so they won't offer as much to COL as other teams and it's even less likely that Duchene includes them as an option even though they're a contender in an attractive destination.

All we really know is that Crazy Patrick Roy thought the organization so dysfunctional, that he quit his dream job because it wasn't close to turning around. The Avalanche haven't stopped falling and their one hope is that last season was just unlucky. Too many teams have solidified their plans with trades and new deals so the Duchene market has closed, one way or another COL is waiting for Duchene's trade value to rise during the season.