Thompson outplayed Nylander in the pre-season. Easily.
Thompson's problem was trying to deke his way out of every situation, and irresponsible drop passes that NHL players won't let him get away with. He's gotten over that, while playing the bench half the time. And doing all that playing with Sobotka for most of it.
Nylander's problem is the engagement and physical aspect. Thompson actually gets the puck on his sticks during shifts because he's out there forechecking with that huge reach and creating messes. Nylander waits. And those players only 'work well' if somebody else on their line is doing all the digging for them. Hence the 'they'll look better in the NHL than the AHL' trope these kinds of players always get. But this is one of the parent club's major weaknesses, and calling up yet another passenger isn't going to fix it.
Nylander did not 'fix the one bad part of his game'. He still lacks engagement when off the puck.
Nylander had all his competition for call-ups traded away, and Smith has clearly outplayed Nylander and earned the first one. Botterill brought in Elie because he wanted neither of these players wallowing in a 4th line role and a healthy scratch half the season. I can hardly say that's a problem. Only problem I see in the club is Sobotka playing ahead of everyone, but that's everyone including Smith, etc.
We have been relatively blessed with little injuries this year. Especially compared to the last few. If we had two of our top-6 guys out, Nylander would be up in the big club no doubt. Botterill likes to slow cook and what's wrong with that exactly? Never was a problem for Guenztel during a cup winning year, but somehow it's a difference maker here?
Casey has the speed and engagement and plays a position sorely needed in the big club. He has progressed all season despite coming out of the gate fat and into December clearly gassed. But I'd be scared to think about this team without him this season. He has not been a defensive liability of any sort. Tage was already up in the NHL, right or wrong by STL, and the problems with his game were easily fixed with some press-boxing. He's more active of a forechecker than a majority of our team-- something Nylander isn't even in the AHL. And you think its just politics that has Tage ahead of Nylander? No, it's just your bias that can't see through players who have different playstyles and why they get treated differently.