Was he new to the organization in Calgary? Come on.
He went straight from Calgary GM, to Toronto GM - meaning it's reasonable to expect that he would have been aware of the landscape of the league, and what teams were thinking.
Let's stop pretending he'd been out of work for 5 years and needed some time to get upto speed.
Again - a ridiculous notion. If he was trying, and willing, to move Nylander, he was able to move Marner.
Marner still has a contract for the upcoming season though, while the same could not have been said about Tkachuk at the time. I believe Keefe was fired because the team did not advance in the playoffs this year (which is also why it wouldn't have made as much sense to make a blockbuster trade after last season's comparative "success"). I also can't imagine that trade talk involving Nylander advanced to a meaningful stage since they ended up signing him to a max term contract with a full NMC.
Friedman said they had Nylander out there, looking for a Dman - they didn't like the offers, so they went the extension route.
Fact that he was willing to move on, but not the other despite the NMC looming, is remarkably shortsighted. He had the opportunity to do so, and we need to stop pretending like he didn't