Was told we looked at them at United as well. The biggest problem wasn't actually the cockpit reconfiguration, but the cabin renovations to match current UA configurations. This would have been expensive and difficult to do since all the new planes need to have cabins initially configured and some existing planes are being reconfigured as well. The supply chain can't handle that much and decided it wasn't worth it so United passed as well. I'm sure whatever economic constraints American saw, United and other airlines are seeing the same issues.