See StrictlyCommercial above, according to the CBA McNally won't be a UFA until August 2016 since that will be his graduating class with his missed year. So it's sign with the Canucks or give up on hockey more or less (with the long-shot hope of taking a year off and then coming back and hoping for a UFA offer).
Unless a GM really likes him, there is no reason to give him a UFA offer in 2016 after missing a year of hockey. He likely won't even get any AHL contract. If he's lucky he might get a tryout in Europe to resume his hockey career then hope he stands out to draw any NHL interest.
Basically his options now are to sign with 'nucks (assuming Benning wants to offer him a contract, that isn't even a surething) or he pretty much gives up any NHL dream (he'll be a long shot with an insanely tough road competing more or less against players 4 younger than him and he needs to clearly out play them to have any chance of getting a roster spot).
The other thing to consider is Utica appears to be pretty deep so even if he signs with us, he might not even play in the AHL next year. Thats something that has to be in the back of his mind. Does he want to delay his degree and possibly play in the ECHL?
It does depend on who we sign for Utica next season but you have to assume we'll bring in at least 1 vet Dman to play in Utica if not more... then you add in Subban and Hutton who are both likely ahead of McNally on the depth chart. Pedan likely will spend all year in Utica as well and you would hope we can bring back Biega. Andersson might or might not stay but if he stays, he's without a doubt also ahead of McNally on the depth chart. Blain is also under contract and McEneny will be competing for playing time too. I believe Cederholm would be there next season too.
Basically lots of competition...