Can you imagine if that happened, but didn't work? Dubas could never step foot in Toronto again, and Torontonians would probably put a bounty on him. But, those are the decisions that GMs are paid to make. I think if things get desperate enough, if they miss the playoffs, go out in the 1st in 5, whatever, whoever the GM is at the time will start looking into a trade like that, but first they'll give the chance to fail to the core they drafted. They've gone out in the 1st three times, and maybe the Bruins are in their heads, but maybe you wait and see if they can miss the Bruins, and see what happens, etc.
They have more than ample opportunity to still trade either Marner and/or Nylander though. Locked in with the contracts, but both are under 25. Marner for Doughty, bring the man home!