Here's a follow-up, and from Automotive News, that the "halocar" will arrive around 2022. The product-portfolio would have to be re-aligned first, with an introduction of a new vehicle every six months. There will also be exclusive V6 and V8 models, as it's also stated that the 4.2L twin-turbo DOHC V8 is Cadillac-exclusive and not shared with Chevrolet, including the Corvette. There will be much with electrification with upcoming program, previously announced, too.
I'm not sure if this "halocar" is one and the same of a production Escala, or something in addition to it. In another report, Johan states that it will not be another 3-box sedan, for the world does not need another, and there will be nothing to compete with Rolls-Royce. I'm posting this on the two threads.
Here's a link to the report: http://www.autonews.com/article/2018...180329610/1168