He would have had that next year as well and had mentioned it was the Leafs or nothing for this season.
I just feel like he could have been in a better spot (better chance to win over the long run) had he bided his time.
Pens are going to be in a world of hurt very soon with little to nothing coming from their pipeline.
The Leafs or nothing was essentially GMing or not. As in he wouldn't choose to leave the Leafs if he was going to continue GMing.
He chose to keep GMing, but then Shanahan had a bad dream and screwed around and the Leafs were no longer an option for him.
Dubas obviously could have waited, and would be highly sought after the next year, but there's never any guarantees about what positions will be open in any given year.
Pittsburgh will be in for a rebuild pretty soon, but he gets to oversee the twilight years of the best player of the previous generation, and set up the next generation, under ownership that values what he brings. The irrational harassment he got from the rabid fanbase here obviously impacted him and his family, so maybe he'd prefer overseeing a rebuild in a quieter market this time.
And organizationally, there are a lot worse places to end up than Pittsburgh. He was offered a raise, significant job security, and a promotion. I don't know why anybody would turn that down. Usually when people take time, it's because either nobody wants them, or they are still being paid by the previous team and new teams don't want to pick up the tab. Neither apply here.