Only thing that I disagree with is the demise of the CT6 in the USDM, although it's continuing in China. They are not going to export from China to the USA, and no other plant in America has been allocated to produce the CT6, once the Hamtramck is done, and converted to EVs. It utilized it's own chassis and had the Blackwing V8. If that stop the Blackwing V8, that's also a serious waste of a great mill and resources, unless, it finds a new home.
There could be light at the end of the tunnel for a flagship sedan-type vehicle, for some speculation reports stated about the Escala reaching production as a flagship, but being an all-electric. The previous Cadillac CEO, Johan (now with Volkswagen) stated, in the past, that Cadillac will eventually have a flagship, but it won't be a 4-door sedan. The Escala is a large, coupe-ish 5 door liftback. Also, in an ad for the XT4 compact crossover, in the street scene, there's a possible Easter Egg in the part where the XT4 drives past a theater, and the markee reads, "Coming Soon - Escala".
Also, other reports stated that GM will have a new range of platforms (for ICE models), prefixed "VSS", and for the rear-wheel-drive cars, it's VSS-R, and that's said to replace both the Alpha and Omega, down the road. Then, Cadillac is set to be GM's EV leader, and will likely produce models on that new and announced flexible architecture that was introduced with that Cruise Origin all-autonomous shared are, and the Cadillac crossover that was previewed in a rendering will be based on it, too. That platform can go from very small to very large to sedan to SUV to vans. I can see it underpinning an all-electric and large flagship. This platform differs from the upcoming, all electric pickup trucks and SUVs, in GM, which are body-on-frame.
This is just my vision and speculation, so I may be incorrect on parts.
Pontiac Lives through BMW and Lincoln - via their split grills and attitude!