Bedard is a winger in the Kane/Gaudreau/Panarin mold. He isn't a C and is just too small/weak/soft/perimeter/bad at faceoffs to play that position.
But he's been hyped as a FRANCHICE CENTER and the NEXT MCDAVID/CROSBY so they're going to just keep hammering a square peg into a round hole because to do otherwise would be admitting failure.
I don't even think it's even really a size thing. Elias Pettersson was rail thin with drafted and had the same is he a centre concerns. He had some Datsyuk-like comparisons though. Where Bedard is Zegras-like in the defensive end.
What's interesting is that he has a similar build to Marco Rossi. Although Rossi is 4 years older. Their situations could not be more different though. Rossi wasn't expected to make the NHL at 18. He was given time to stew and made the NHL full time at 22( he did lose a development year because of covid though). He also has Kaprizov and Zuccarello as wingers, and Minnesota also has one of the best 2way Cs in JEE to take the heavy matchups. While Bedard has had mostly washed up Hall, Foligno, and a declining Turovainen ad wingers. He's playing C when his defensive game isn't close to developed, with no other C to take the pressure off. Also the standard rebuild culture of bad coaches and players does not help.
In short. It's not that he is too small to play C. It's that his defensive game can't make up for the lack of size. Plus the worst development conditions possible does not help.
Looks like they may be moving him to wing though.