One of the goals after the merger (and the stated reason for canceling US Airways’ A350 order), was that they wanted to reduce fleet complexity. This is at least part of the reason they are phasing out the E95 this year. By 2023, they will only really be operating about 14 different sub-fleets. This is less than DL or UA, who have less total aircraft.

I do hope they pick some up in a few years though.