It's probably also worth noting that the Amerks are in second place in the AHL, and they are playing at Charlotte on Friday and Saturday. Charlotte is best team in the AHL, so it's a big series. The Amerks also play at home against Utica on Wednesday. My guess is that Nylander's call up is based on him having 4 goals in his last 4 games - i.e., it's legit earned - but the upcoming schedule explains why they didn't call up Olofsson or Asplund or CJ Smith or Leier or any other guy who has made a case for call up recently.
I'd be shocked if this isn't a showcase and Botts doesn't trade Nylander this offseason. I'm not saying that's a great idea, but this whole thing certainly looks like it lines up that way.