He does have more leverage though because he has the option of demanding a $9m minimum salary or he goes straight to UFA.
Advantages of being a UFA... he can go to UFA market with multiple suitors... likely nets him a larger AAV contract and he gets to chose the team/city he wants to play in.
Also, he could be a dick and make it very well known that he is asking for $9m (qualifying offer requirement) or he is going to FA. If he ends up doing that, he may take less money in the end, but he gets to pick his own destination to play in. I hate Tkachuk and the Flames but, selfishly, I would hate to see this start to become a trend... small market teams, especially Canadian ones, have enough hurdles to jump through than to start to see that as a trend. If Tkachuk does take that approach, his value in a trade could be diminished significantly - more risk on the acquiring team.