There’s been rumors of a Chicago street course for years. I think it’s dumb.
Street courses are a logistical nightmare, and there’s not many places you could go that would lead to good stock car racing. Street courses (debatably) work in F1, but even then, most of them are some of the worst races of the season(looking at you, Monaco)
Street courses aren’t entirely foreign concepts in NASCAR. The old Daytona road course was ran partially on the streets and partially on the beach, but the cars and times are different now.
NASCAR might get a decent ROI the first time because of the novelty and curiosity, but I don’t think it’ll be a success in the long run