I was talking to folks who did this in the southeast. Compensation was the problem, not location.

For those folks, sure. For many others, the location could very well be. You won't know because many people probably only look at job ads filtered by location, so they just ignore any that are in "undesirable" places, whatever those may be.

Super low cost of living on a tech salary? Sounds good to me. But if that doesn't work GM has the Cruise offices in San Francisco that they'll have to find some use for. GM proper also has offices in North Hollywood and Pasadena. Cadillac famously used to have offices in New York for the prestige, but Cruise still does AFAIK.

I'd bet that the problem is absolutely going to be more of a bureaucracy and salary issue than a location one. GM is a hilariously broken company and I can't imagine an enjoyable one to work for.

GM has many development centers, including Roswell, Georgia, but it should be pointed out that like most American metros, Metro Detroit has a wide variety of cities and towns for different lifestyles. You don't have to live in Robocop to work for GM, which has facilities spread about both the Detroit metro area and the country.

And since software is built in big factories just like cars are, there is absolutely no way for those engineers to build those systems without moving to Detroit.