Send any good NHL player back with modern equipment and training then they would obviously destroy the league (maybe not to Gretz or Mario levels), but you can't examine things like that. Matthews wrist shot and puck control wouldn't be the same without a tailored composite stick designed with an ideal curce, flex and kick point to maximize what he wants out of a stick. Current goalies with modern equipment allowing them to easily play in a butterfly without the weight of heavy pads weighing them down would also excel. More than any of the other big 4 sports in North America (and you could add soccer), hockey has been the most heavily altered by just technological advancements in equipment. I think it was at a Leafs outdoor practice/skate a couple years ago that Rielly and Gardiner tried using old-school wood sticks and almost lost their mind.
Matthews is a great player and I'm sure would adapt to the equipment of the 80's and excel. But, while his current shot would destroy goalies of that era, the equipment he uses to maximize it wouldn't exist. No one is giving him a sakic/yzerman curve, with a low designed kick-point at 80/83 flex to shoot like he does now.