He was a 1st liner for the Czechs, so he was playing against the best the other team's had to offer. I know he matched up against Malkin's line against Russia and Blueger's line against Latvia, but I'm not sure who else he played against. The Czechs lost in the bronze medal game to Russia and went 6-1 in the tournament as well, so they obviously had success with Simon in that role.
On paper, the only thing I think you can knock for in regards to playing center in the NHL is his strength. I think he has the hockey IQ and playmaking talents to be able to provide some upside offensively, his defensive metrics are also extremely strong and he has had success with the Czechs at center. It's definitely something I want to see tried, and if it doesn't work, there's no harm there.
I will say though that Simon gives me Janmark vibes with his ability to play center. Like he may be able to play center full time, but you'd probably get more out of him on the wing. Ironically, I think Bjugstad is arguably in that group too.