It is, but what no one ever mentions is shots per game. His shooting percentage is almost guaranteed to go down, but that doesn't automatically mean he will score less.
Last year he had 80 shots in 63 games with the Rangers and scored 18 goals. In 2014-15, he had 179 shots in 81 games with the Islanders and scored 17 goals. That's almost 1 extra shot per game. If he spends significant time as the 2C, I can definitely see his shots per game being higher than it was last year, which will help offset a lower shooting percentage.
4 of his goals last year were on the PP. PP time can inflate his goal totals even if he isn't shooting at a high percentage 5 on 5.
We need to see how Quinn uses him this year, but it wouldn't surprise me at all to see him have a career year.