Aircraft in the 200-250 seat segment virtually not exist, so they are hard to find on these "global flight analysis" charts. The price question is: will airlines always and forever fly the same pax-range as they do today, or will they switch to other aircraft if available.
Given the high number of frequencies between some cities larger short range aircraft can make sense (but don't need to, if airlines prefer to keep frequency).
The current standard aircraft (A320, B737-800) were designed with the stretch in mind, so they are heavier than really necessary for the mission.