Yeah, Tkachuk's was definitely a special case and I think it's the only actual sign and trade that happened in the NHL. However, it's possible that a different case does arise.

The incentive for having a Matthews sign and trade would be that the acquiring team doesn't lose their investment in Matthews with him having 1-year and full trade protection. Any team that he's willing to waive for probably wouldn't agree to a sign-and-trade, since it returns leverage to the Leafs. Instead, they would offer a package that they wouldn't be devastated losing for 1-year of Matthews. Then try to resign him after the fact.

Because; ‘Merica.

In the above scenario, it's highly unlikely unless Bedard pulls a Lindros too. I don't see him doing that to Anaheim (maybe Arizona) unless he hates McTavish.