I do think the title is misleading though, by conflating "Detroit" with "The Big 3" (General Motors, Chrysler and Ford).
Detroit itself is already well on it's way to diversifying it's economy and particularly making investment in tech. There is what's known as "The Family Of Companies" (1) referring to a whole fleet of businesses supported by Dan Gilbert of Quicken Loans and many of them are in tech and in the buildings downtown. Gilbert himself owns something like 30+ buildings in the Detroit area.
There is a start hub near by as well in Ann Arbor which has recently produced companies like Duo Security and FarmLogs.
Real estate/cost of living here is much cheaper than in most of the bigger tech hubs and it's bringing all sorts of companies.
There is a somewhat valid critique that salaries aren't quite competitive for tech, but I've found the quality of life has been quite nice. For ex: I know several people coming out of bootcamps with or without degrees and making 70/80~k with 1-2 years experience, but with rent being only 700-1k for your own apartment ( less with roommates obv ), you wind up putting away plenty at the end of the month.
In my opinion, it's actually a pretty great place to live and is handling the shift of becoming a tech city quite well.
(1) https://www.quickenloans.com/about/partner-company#chat_clos...