Yes, his value is lower at the moment, however, if he continues to flounder again next season, his value will bottom out. Trading him this offseason avoids that, while allowing the recieving team to continue to think he'll bounce back with them.
Now, it sure to hell doesn't take a modern day athlete a month and a half to get into game shape. That is a ridiculous excuse IMHO.
A 33 year old Shea Weber returned from surgery, to repair an injury to tendons in his left foot, after a six month recovery. It looked like he didn't miss a beat scoring 14 goals and 19 assists with the same number of games as Nylander. So, how does a 33 year old outperform a player 10 years younger?
If it takes playing with Matthews to perform, then, IMHO, Nylander is not worth his salary. At his salary, he should be able to drive a line by himself. It was Daddy and his agent that wanted Nylander to be paid as a 2nd line centre, so, it was up to Nylander himself to prove he could at least drive a 3rd line. The Kadri suspension gave him that opportunity, and, he failed IMHO.
If Dubas keeps Nylander, let's hope he returns to being at least a 20 goal, 40 assist player next season. If he doesn't do that, it'll kill his value in future trade scenarios for sure.