It seems that Delta just straight up is trying to reduce the amount of their regional partners. I don't think it's a matter of them playing "scare tactics" or using "smoke and mirrors". Delta just plain doesn't want "elevendy-billion" regionals flying for it anymore.
I hate to say it, cause i like pinnacle, but I think (just like freedom) that Delta will probably just buy the rest of the contract out (or pay an early termination if there are terms for it). Even though they don't own the 90's, they still have some on order, and as part of some of the domestic roll backs could downsize these routes to 70 seaters for the time being, which ASA and Comair have a ton of already in/out of ATL frequently.
Good luck guys and gals.