There probably is something to this. I think the Jets definitely overperformed last season relative to their talent. The reason the record in one score games is a big deal is the decisive play sometimes comes down to a lucky bounce in games like those that goes the winner's way, like two opponents committing 15 yard penalties to set up winning field goals. This shouldn't take away from what the Jets did. They took advantage of those opportunities, but it is unlikely they will get almost all of the bounces to go their way again.
With that said, I think they are underselling the improvements the Jets have made on offense. I could see this being around a league average unit. The big upgrade is at quarterback. The Jets are either going to have Michael Vick or Geno Smith will win the job by improving to at least Vick's level. That would represent a huge upgrade over what the team got last year from the most important spot on the field.
I would be disappointed if the Jets regressed to the point they were not competing for a Playoff spot. You can have flaws and still land a six seed.