I think his point was the 7ER is underpaid in the current contract relative to other equipment.

As far as the eternal 100 seat jet debate. I have heard all the same things since 1991 when the DC9's were retired. The last 100 seat jet Delta purchased was in 1983 or almost 30 years ago. Management spins up the 100 seat rumors every time something is in play in the contract. The reality is that they don't want a 100 seat aircraft. It wont even be a big issue in the contract. They might open for one at DCI but it will be a throwaway item.
They are on record over and over again as stating they can fly a 150 seat aircraft for almost the same trip cost as a 100 seater so why go any smaller. The consider that the break point on trip costs verses seat costs. They might purchase something in the 130 to 140 seat range if it offered a big jump in efficiency but you will never see a 100 seater.