I thought Thrun was the best defenseman at the WJC18. He didn't make that many big plays, but he might've made 1 or 2 bad plays in a 7 game span. He played an incredibly good tournament. Thrun has a tendency to play very consistent and very inconsistent. By that I mean that he has stretches where he can go a number of games playing a very good game in all zones, and he looks like a top 20 pick, and then he has stretches where he plays 2-3 very bad games in a row. His form fluctuates a lot during different stretches of the season, and I've seen tournaments where he plays awful and tournaments where he plays great. When he struggles, he's usually trying to too much offensively. He's capable offensively, but he can get caught with poor positioning in all zones when he's trying to do too much offensively. It doesn't help that the NTDP gives up a lot of odd-man rushes.
In a draft that lacks many top-end defensemen, I think he could find his way into the late first, although early 2nd wouldn't surprise me either. The other thing to keep track of with his draft stock is his college commitment. He's going to play at Harvard next season. Two of the last 3 big time prospects from Harvard have caused trouble for the team that drafted them with the free agency loophole. That could cause his draft stock to drop.