What letangerang said right here:
The fact is teams that are deep with "middle tier" players such as the Flyers and Bruins will continue to be consistently dominant while teams that are top heavy in talent like the Pens will fluctuate between seasons.
contains a hint of the main reason why I think a cap on contract length will not affect the middle class as much as people are saying.
GMs know that it takes a well balanced roster to consistently win, and spending too much on just a couple players could be devastating to their depth unless those players are a Crosby or Malkin who can make up that difference.
So while the Crosbys and Stamkos will definitely have a higher cap; I have a hard time seeing Parise and Suter getting deals that would be much higher cap hits than the ones they just signed because they are just not worth it to take up that much more cap allocation in order for a team to fill out a more balanced roster. I like to think that most GMs see this, but as we all know there are a few nuts out there that will do anything even if it hurts their teams ability to win.
On top of that, if we go with that Parise's and Suter's contracts wouldn't have a higher cap hit, then it would be a positive for the rest of the players in the league because those front loaded deals wouldn't screw up the escrow stuff for them.
That's just how I see it. The players that are important to winning will always get paid the majority of time, and there will always be some that are "overpaid or underpaid" in our eyes.