I suspect that it's a nothing burger. A lot of folk in minority neighborhoods move a lot and may never receive them or may never mail the application back in or may never receive the absentee ballot itself or may never mail that in. It's a lot more complicated than just showing up to vote.
Link: https://www.freep.com/story/news/politics/elections/2020/05/19/all-michigan-voters-get-absentee-ballot-applications-in-mail/5218266002/