I don't think so.. we are not talking about the same thing at all.
Matheson has 2 more years at $6.5M/yr, while Tanev and Hanifin are in their last year, at $4.5M and $4.95M, respectively.
One is a medium-term investment, the other two are playoff rentals. They won't retain on Matheson over such a term.
At this point, most contenders don't have that kind of salary cap this year and in the years to come. They will likely prioritize players that will need to be signed at the end of the season before adding a $6.5M salary.
The only player with some value right now is Savard, and it's a mixed feeling whether it's worth getting a 2nd round considering the impact on the development of the rest of the team. Montreal already has so many picks...
My guess? Montreal will move if a very good offer is made (ie a 1st round), but otherwise, nothing will happen at the trade deadline. They are more likely to make a move akin to Newhook at the draft, to transform draft picks into players that are closer to the NHL.