What incentive is there for Matthews to do that? His NMC kicks in July 1st, why would he do a sign and trade when the ability to choose where to go would soon be available to him? Plus the team he wants won't have to gut their roster of assets
It's a little counterintuitive, but if you look through the history of all NHL players, guys are usually happy to "stay put", so long as they feel "their value" is being met.
That's why you saw Huberdeau sign an extension, despite being blindsided and having never played a game in Calgary.
For most NHLers (esp in the upper tier), it's not even about the money, it's about how they feel they are valued by the team, and money talks.
That's not to say he'll happily sign in Winnipeg or Buffalo or Ottawa.... but as long as the destination is reasonable, the acquiring team will know that they've got a decent chance at signing him.
Personally, I think Dallas could be a bit of a darkhorse candidate if Vegas finishes them off. They're at risk of falling off with Seguin & Benn getting older, but have a really good young core with the likes of Hintz, Robertson, Heiskanen, Oettinger.