New 175s announced. This isn't even counting the forecasted 20 Compass birds.

American has just announced that it is exercising its options for 15 additional Embraer 175 (E175) aircraft, to be operated by Envoy. These new aircraft are expected to begin arriving at a rate of three per month, starting in early 2020.

This is in addition to the 25 E175s currently on order that begin arriving later this month and continue through 2019. By mid-2020, Envoy’s E175 fleet will have nearly doubled from where we are today:

We will have 84 175s when all this shakes out and again, that's prior to any Compass birds arriving.
In addition, Envoy is expected to flow just under 700 total over the next two years alone.