Technically, yes, but not universally. As it was, we were frozen at 153, with no way to increase without trading in an equal number of 70-seaters AND increasing mainline airframes above a certain number. Now, Delta can add 76-seaters simply by buying 717's (which they arguably might have done anyway) without having to trade in 70-seaters.

That said, there was a way to get to 255 76-seaters under the old contract, and now Delta is limited to a maximum of 223.