Certainly possible that Delta could downgrade that 717 flight as the flight gets closer -- Delta is known to adjust capacity a couple of months out. However I think this...as well as a single LGA-BUF flight staring in September...represent the first mainline flights for Delta on their LGA network outside of Florida and New Orleans. So this might well "stick" more than the routine adjustments from CR9 to CR7 to E75 that happen in the LGA system.