I've said this many times, and it always attracts a certain poster who wants to rebut it with "BUT WHO ARE THOSE YOUNG PLAYERS WHO ARE BETTER THAN BUCH? HUH???"
Yeah it's obvious we have wings to spare. Kakko, Kravtsov, Lafreniere, Kreider has a long term deal and is going no where, Panarin has a long term deal and is going nowhere, Gautier is an option, Barron is an option. Yes Panarin Kreider and Laf are all LWs, but if you have big money tied up at LW, you don't need big money tied up at RW in non superstar players. You go with support players or younger players on the opposite wing of Panarin who are not as expensive and who do the dirty work.... or you wait until you have another legit star there like Kakk0.
Buch is simply not getting paid market price on a long term extension, and that means he's eventually gone sooner or later. And if he's eventually gone, it's more important for this team to capitalize on high value in return than it is that he occupy a roster spot to try to sneak into the playoffs or shield the kids... there are other vets who can do that.