There was a *lot* more baked into the decision to drop Amazon than is displayed in those numbers. Amazon was playing a very smart game, using FedEx lift to move its lowest yield packages (thereby taking real advantage of the cost negotiated with Purple to move them).
The "revenue potential" that was lost (which was only 3% of Express' overall business) was producing only razor-thin profit margins anyway. What most folks didn't realize was that at the time of the divorce with Amazon, Purple had more domestic business than it had airlift to accept, and that other business had higher profit margins than the Amazon packages. Without Amazon, Purple is now free to go after that business that had previously been rejected.
What has *really* been hurting Purple financially recently is the combination of the China trade war, Brexit, and TNT integration. Those three have been massive punches to the bottom line, and are what is really responsible for the "we made less profit than Wall Street folks think we should have made" doom-and-gloom news of the last two quarters.