I'm not an expert on this subject whatsover but I doubt the sale of Mesaba and CPZ had anything to do with flow thru. It may have been icing on the cake, but really was a none issue.
I think as pilots we all think too much about our personal feelings, and less about the business side. This was just another way for DL to make some quick cash and keep cost down on the regional side. The whipsaw is alive and well!