NJ doesn't need him to be a point per game player, they have enough of those. What they needed was to get bigger, more physical, and more difficult to play against.
If he scores 30 goals and plays like a bastard in the playoffs - that's all they need from him. He didn't get many points in the playoffs last year, but he was definitely a disruptor on the ice and made some major contributions in the Rangers series that didn't show up on the box score.
That being said - he has been playing with his head up his ass the first three games. I don't mind the lack of production, he started slow last season not scoring a goal until Game 10 but still finished with 40. He scores in bunches, that's fine. It's the stupid, lazy, unnecessary penalties that are hurting the team. Ruff was correct to bench him in the 3rd last night, and once he did the team responded by coming back from 4-0 down to nearly tie the game in the final seconds.
He's far from the only one. That whole line has been lazy and low energy. Hischier and Mercer are also having a really terrible start to the year.
It will get figured out, NJ has too much talent for this not to work.