Only to those who were looking at his stat line and not how he was scoring those goals, or what his limitations as a player actually were.
The odds of that happening were always very low. Because while NJ plays with speed (which is Grabner's forte), his only asset is his ability to create chances due to his speed. I screamed this very very loudly at the time (and then was overjoyed that he wasn't traded to PIT) that he couldn't cycle the puck, that he couldn't work well with others to get them the puck, and that the odds of him even coming close to what he did in NYR was very remote, and that the Grabner that NJ was going to see was the same depth guy Toronto saw. NJ and NY played very different styles - both involved speed, but that's where they ended. And when Grabner went to NJ and stopped playing in a system that catered to him and instead was asked to play in a system that was focused on possession hockey, he showed exactly what many thought he was.
I'm not saying that what Grabner did in NY was a fluke - it wasn't. But that success was extremely dependent on the system that NY played that catered to Grabner and his abilities by using the stretch pass, where he could frequently score off the rush (either on a breakaway or by being fed a pass by a highly skilled linemate).
Anyway, his failure in NJ was predicted by several people who could look past the numbers and his speed and see how he actually played the game. And that even with Hagelin getting hurt in Pittsburgh's last game, I'm still thankful as **** that Pittsburgh didn't trade for Grabner.