Highly unlikely that JetBlue intends to start scheduled service at Chicago-Midway.

I remember that JetBlue delayed their entry into the Chicago market until they could get gates and slots at ORD (Chicago-O'Hare).

So far, they have very limited service at ORD, just LGB and JFK. I really can't see JetBlue adding a second Chicago airport or moving their service from ORD.

Possible explanations: charter flights; flights to one of the maintenance facilities at MDW.