I fantasize about such non aggression pacts yes, where say the governors of say KY, TN and IN, call the gov of NY and say, if you do that map we say, these three guys will be tossed to the wolves. Alas my fantasies are not co-extensive with "a thing." 
The Governor of Kentucky is a Democrat
Yeah, whatever. The fantasy is the thing, and the narrative, not reality. I don't think the governor has a veto there by the way.
He doesn't, but he does have some state supreme court rulings from last decade about minimizing county splits on his side. The one remaining Dem district can fit entirely within one county and is guaranteed to be a Biden district if it continues to be.
Jefferson County is way too big to be a one single congressional district.
That's his point. They can easily continue the current arrangement, where KY-03 is contained entirely within Jefferson County, but not all of Jefferson County is in KY-03.
