It seems more than likely. GM has not been able to make it viable for the US market. I think the likely scenarios are that some european buyer will take it and will pull out of the US, or that it will just be folded into Opel and assets and the brand will die. Either way, as a Saab owner and enthusiast, I will be sad. What will the professoriate drive?
But the question remains, why on earth continue to focus on Buick and GMC. Buick's audience is dying and serious luxury buyers will look to Cadillac, which GM resuccitated nicely, and GMC is just rebadged Chevy trucks, no? Chevy and Cadillac are the the core of the GM empire (with Opel in Europe), who needs anything else?