Diesels are not going anywhere in NA. People buy the little Volkswagen TDIs left and right, and RAM has a diesel half-ton pickup.
I think part of the "dirty" aspect is a push to get all vehicles except EVs out of countries. This works for Europe because they such a small area, but not for most of the world.
GM seems to have missed a lot of boats. I don't think RVs are a big thing, but they really need a Euro style van, and not just to stuff a small engine into an existing model. Even if they just rebadged something like the Hyundai Hg350, that is a lot better than losing a market.
I used to like GM... but it gets me wondering what they are doing. Only Cadillac seems to be doing innovations these days, it seems, within GM.