The Vault of Midnight comic book store's New Center area location has a small space allocated specifically for local artists, which don't necessarily have to be comic book artists. The address is 2857 E. Grand Boulevard.
Although it was the case that Cass Cafe and Great Lakes Coffee showed art in exhibits of fixed or roughly fixed duration, I considered both of those places to be restaurants that show art as a non-primary activity, and therefore they didn't count as art galleries.
However, Cass Cafe was more serious about art exhibitions than perhaps any other restaurant in Detroit, with new exhibits announced in the Art Detroit Now newsletter on a fairly regular basis. But both of Cass Cafe and Great Lakes Coffee went out of business, though for different reasons.
Motor City Brewing Works sometimes has little one-night solo shows on Wednesdays. The address is 470 W. Canfield.
Another place, south of Cass Cafe and Motor City Brewing Works, is the Detroit Shipping Company. I think it opened in 2018. There have been art exhibits there almost the whole time it's been open. The address is 474 Peterboro.
To deal with the coronavirus pandemic of 2020, many restaurants were forced to either limit themselves to curbside delivery or go out of business. This meant no art exhibits in 2020 or 2021 in restaurants that had been exhibiting art prior to the pandemic. As things slowly return back to the old normal (though it's not certain that's possible), some restaurants have started showing art again.
The lobby of the Crain's Communications headquarters has been refashioned as "the Gallery in Brewery Park." Unfortunately, most openings are for narrow windows of time on Saturday afternoons, rather than in the evening. The address is 1155 Gratiot.
After moving from Ferndale to Detroit, The Butcher's Daughter moved to New York.
Kunsthalle Detroit is believed to be permanently closed.
I don't remember exactly when the Marygrove College Art Gallery closed. Or if it never did really close. The address is 8425 W. McNichols.
Inner State Gallery closed on December 16, 2017. The owners might start a new gallery with a new name at a new location.
City Sculpture is more correctly considered to be a museum rather than a gallery.
There is quite a bit of a connection between Birmingham and Detroit: Like Wasserman Projects, Reyes Projects could also be said to have moved from Birmingham to Detroit.
Blackbird Gallery moved to Farmington Hills.