It'll be interesting to see, though my experience is that people are insulted by Trump talking about criminal justice reform as if it's just for the blacks because obviously we're all in prison.
I think black male turnout is going to be generally lower from millennials on down, but that's because no one left will be talking seriously about reparations or creating a free black state and funding initial infrastructure for it or whatever. The sense I get is that black males who are younger than me are more ready to give up entirely, make as much money as possible, and try to use that to insulate themselves from the issues of American society rather than working to grind out political compromises in the name of incrementalism.