GM missed the boat several years ago. While Ford/Dodge/Merc were introducing the new modern platforms and ditching the older technology, GM sat around and did......nothing.
Next time you go out for a drive count the number of Transits and Dodge Rams that are out there. They dominate the market segment. It won;t be long before the Transit (with Dodge as a distant 2nd) will dominate the smaller class C market.
It's going to be tough for GM to dominate - they have to play catch-up for a number of years unless they introduce something which is much superior.