I disagree. Cadillac has shown many concepts that become production. The Escala concept is applied to the XT4 and XT6, and updated on the CT6. The other previous concepts, such as the Elmiraj and Ciel, do appear on other Cadillacs. The Evoq is the ELR, and there are more than what I remember of all the Cadillacs since riding in my uncle's white convertible Fleetwood in 1956!
Elmiraj was a great concept but the fact we still don't have a modern version of the classic caddy pimpmobile is disappointing. Even Lexus beat them to the races on this one.