Hyman should be on Team Canada because he's one of the 14 best Canadian forwards alive, full stop.
He's closer to 14 than 1:
Locks:
McDavid
MacKinnon
Point
Marner
Crosby
Bedard
That's 6 forwards right there. I don't think anyone will argue that Hyman is a better hockey player than Barzal, Thomas, Stone or Scheifele. That's 10 forwards. This is where you can start to discuss Hyman along with players that will fill roles for Canada such as Reinhart (2-Way Playmaking Winger), Verhaeghe (High-Volume shooter), Konecny, Cirelli or Hagel (Forechecker, Agiator, PKer), Danault (Shutdown centre and PK specialist).
Or you opt to go with veterans to fill in your remaining roster spots such as Stamkos, Marchand and Marchessault or youth in McTavish, Jarvis or Byfield.
IMO, I think Hyman's duties can be fulfilled by others. No one is saying Hyman isn't a good player or debating about what he would provide for Team Canada, just that there is better options. In reality, Hyman has a good chance of making it because Hockey Canada really likes chemistry. That does not necessarily mean he's the best option.