The solution is obvious.
The museum, apparently, is not generating enough revenue to keep on keepin' on. The city of Detroit has a long line of very immediate physical needs that it needs to address before sweating existential blood over cultural aspirations.
Gaseous, silly pronouncements that attempt to make it out to be some philosophical battle involving "truth & reconciliation" vs. "popcorn & swag" are fine for endless bar-room debates held over multiple pitchers, but Detroit ran out of that kind of time many years ago.
If the museum is losing more money than it's bringing in, and no benevolent philanthropist is stepping up, with an assist, to keep its doors open, it should close down.
There is no shortage, around here, of folks who harbor a plethora of ideas-- fantasies, perhaps-- about how things should be, could be, etc.
The shortage, as always, is evident when it comes down to the question, "so who is going to pay for it?"
Fanciful notions of how important it is to maintain a record of African-American history may be well-meant, but benevolent intent has no redeemable cash value.
It's losing money, but you want it to be open?
Pay up, or shut up.