Ofcourse they have a choice. Marner has a NMC and holds all the cards right now. But the Leafs are not obligated to re-sign him, just like he didn't feel obligated to take a team-friendly deal.
If the organization's concern is more about losing Marner for free, then it is a choice of their own making. I see a lot of Leafs fans complain about Marner's off-season production, his "softness," and his contract. Do they think any of this changes if they re-sign him? If not, this is just going to be a repeat of his last contract.
I asked 8 x 11.5M with a NMC. Is that acceptable?
Also, is that acceptable for the type of player he is, going with the assumption that he is not going to all of a sudden become tougher to play against and become a better performer in the playoffs? Sure, the team can afford him because of the rising cap and the expiring Tavares contract but the question is should they? Is he a good fit for the team going forward?
To me it just seems like a lot of Leafs fan want him re-signed simply because they don't want to lost him for nothing. It's just me, but seems like thats the wrong way to go about building a team the right way.