CA rescinded their feel-good law. They had to - no manufacturer could meet what those technology-deficient, self-serving clucks cooked up.
Yes - an electric car is expensive to produce. /and any manufacturer could produce a real-world 60 mpg car today - with good crash protection, too. It would weigh 1,500 lb., would have a 1.0 liter engine, skinny tires as hard as a rock and slippery as h*ll when it rained or snowed, would be blown around if there was a stiff wind, and would be constructed of carbon fiber, magnesium, titanium, selected application of high-strength steel...and go out the door with a $35,000 price tag.
Auto manufacturers for a long time, have been required to have parts available for vehicles up to 10 years old. There is not a single part that cannot be obtained by a dealership, and usually in 24 hours. It's part of doing business, and they are good at it.
GM, like any manufacturer, would sell you lard-on-burnt-toast sandwiches if they could make a buck on it. Same with electric cars.
Developing and manufacturing any new vehicle involves hundreds of millions of dollars of capital, labor, testing, setting up supply lines, marketing and so on and so forth. It's not the same as a fast-food company issuing another variant on a hamburger...