That even assumes that ATL is some golden goose market. Its many multiplies bigger than its O&D demand because the excess is used by DL (and a lesser extent SWA) as an arbitrary hub. First of all there is zero chance anywhere close to that total number of gates would go to the feeders of ME3 and NAI scab FoC type airlines. It would probably be a small fraction of that. DL would likely end up with a significant amount anyway, and most of the rest would go to so called LCC's that don't code share with the vermin airlines you mentioned.

IOW, empty threat. Oh, and to any extent that SKYW actually has a say, which is very little BTW, DL would easily be the highest bidder for most of those gates, which they would desperately need the money from (again, even assuming they had much of a say) because if they did that then by definition they were losing a massive amount of their revenue and guaranteed profits. There is zero chance (again, even if they had a say) that they would pass up more money in order to try and harm a DL out of hubris.

Not worried about it in the slightest. But SKYW should be.