To me what's most impressive about Zonnon's season is how quickly he got used to the center position, when as far as I know he had only ever been a winger before this year. He adapted really well to being thrust in the 1C role on a pretty good Q team. Even his faceoff % improved noticeably over the course of the year: in October it was at 45.3%, in March it was at 53.6%.
He's an intelligent, hard-working forward whose best asset is his top-tier playmaking. He has great vision and can thread difficult passes with his forehand or backhand. He has a nice frame, and he's pretty physical, but it's a side of his game that's pretty raw, and he loses more battles than you'd expect for a guy his size. Shot is ok but nothing special.
The big problem with Zonnon is his weird skating mechanics. Yeah he can get really fast once he gets going, but his acceleration and overall agility are really poor, It's something he'll absolutely have to improve if he wants to make the NHL.
His realistic upside is probably solid bottom-6 guy. As great as his passing and vision are, he doesn't have the overall tools to be a top-6 NHL player. But that's true of most forwards picked in his likely range (late 1st/early 2nd).