I've been critical of Sakic, but I think this idea of keeping Nate, and ROR, or Duchene, or whoever, is a bit of wishful thinking.
There's a pretty strong butterfly affect to trading key pieces of your team. Especially for a team that has basically sat at a fork in the road after each of the last few seasons going back to post 2014-15, deciding whether they wanted to go down the path of a rebuild/retool, or push forward and continue to supplement the group they had.
After they went down the path of trading ROR for assets and young players, it set in motion a series of events that are likely to happen now. It reset the competitive window, and that ate of the remaining years of some guys contracts. Duchene was one of those. When they got younger with the ROR trade, the team just wasn't going to be cooperative during his contract. He'd be due for a raise, and that would have an affect on the younger guys that would be due their own raises in the coming years.
Same goes for Barrie. The team just isn't going to be competitive during the remaining years on his contract. This will most likely lead to him being traded because he'll cost too much to retain, and pay for the raises of the young players they've added for the future.
Same might be for EJ, except they don't have anyone right now that could ever replace what he brings. Z is the closes, and right now he's pretty far off from the level of play, and stability that EJ contributes to the team. So he might stay for the long haul. Not to mention he has a NMC, so they'd have to ask him to waive.
Varly's in the same boat. His contract and age would put him in the group to move on from, but the goalie market is so thin, it likely will be better to just resign him. Hopefully with a medium term contract like three years or so. Unless Martin somehow ends up in the starter role next year and proves he can replace Varly.
These are just the decisions of building a team under the cap system. You have to plan according to a certain window you expect to be competitive during, and make sure your key pieces are under contract during that time.
Once you start adding a certain amount of young pieces like Mikko, Compher, Jost, Kerfoot, Girard, Zadorov, Makar, etc and they show signs of being good top 6 or top 4 contributors, it becomes a team that they will inherit. That's where we're at right now. You can see the massive chemistry change. Those young guys are big pieces of the team, and they know it. They've formed a bond, and the wins and losses come based on their performances. It's their team. Not older vets, or stop gap players waiting for the youngsters to get older.
The key parts of the older group move on, and the ones that were the "young guys" under the previous group (Landy, MacK, EJ) become the new stars and leaders of the team. They are the guys right now, and they're forming a new bond with the new young guys.
So many of the good young players that have turned around the peformance of this team, and changed the bad mojo in that locker room, probably wouldn't have been here if they went down the path of trying to compete with too many of the guys from the last rebuild/retool group. The Stastny's, the ROR's, the Duchene's, soon to be the Barrie's, etc.
There just isn't enough room in the lineup, or money under the cap to be fooling around much. You believe in what you got, and you go all in. If they were still all in with Staz, or ROR, or Duchene, they just wouldn't have had the money, or the assets, or the tanking seasons for high draft picks, to have the pieces they're about to go all in with now.
That's why you can't usually just go from one competitive group to a brand new competitive group over night. It takes time in between.