The only thing they can do without the players consent is to buy him out as he has a full NMC. Thats 12 years of cap hit although the first 2 are painless cap wise.
And I am not sure if you can buy out a player who’s in the program. Probably not as you can’t buy out an injured player either.
So I think they are stuck with him for at least 1 season unless he consents to a trade. I’m not sure who takes on 6 years of a player 1 step away from Stage 4.
I wouldn’t be surprised if they loan him to a KHL team once he is cleared to play again.
Contract length probably is a non issue is my guess.
The issue is do you want 6mil of cap tied up in a guy that could very well burn you after the trade deadline or in the playoffs when you can't doing anything to replace him. That and depending on the makeup of your team do you want him around your team if you have younger high end prospects?
And of course I don't see how anyone is giving up any real assets for him either.
The whole loan part would be very interesting though and I'm sure even if he's in the KHL he will be getting tested on a regular basis by the NHL which could lead to the contract being voided if he continued to slip up.