In fact Mesaba turboprop FO's were making more than Pinnacle JET FO's prior to the JCBA. In fact they still make more in some cases under the grandfathered rates.
I've heard this over and over again, and it's a useless statement. Guess how much XJ pilots will make on the Saab when a Saab is parked in the desert? $00.00/hr. And all but 7 Saabs are headed that way! By the end of next year, there will not be a single Saab in Delta colors under Mesaba or Colgan.