Was wondering about that dam myself. No coincidences. Damn. I like the questions your asking agree anons must dig time to get digging. Will try myself as well.
Boyce Hydro was "in violation of numerous provisions of its license" and the CBS News article said it was in the process of being sold.
https://www.federalregister.gov/documents/2018/02/26/2018-03821/boyce-hydro-power-llc-order-proposing-revocation-of-license
The Four Lakes Task Force was set to purchase four dams and lake bottoms from Boyce Hydro, expected to have been signed in June 2019.
https://www.mlive.com/news/saginaw-bay-city/2019/04/wixom-lake-to-become-a-lake-again-after-tentative-9m-deal.html
Board of Directors for Four Lakes Taskforce - looks community-led. But they knew at least as far back as 2017 the dams couldn't withstand the maximum expected pressure.
http://www.four-lakes-taskforce-mi.com/about.html
Problems with at least the Sanford dam seem to go back a very long time. See this article from 2013, when an owner of Boyce Hydro is expressing frustration that they can't get funding to fix the dam, it isn't profitable enough to fix on their own, Consumer's Energy won't increase their payments for the dam's output, community doesn't want a bond to pay for it. So because the dam couldn't be fixed, they were forced to lower the lake level by 8 feet to ensure it would hold at maximum flood level, thus rendering all lakeside property no longer "lakeside" - reducing all property values and making the lake less usable. The timing of the breach is suspect but this seems like an old, bureaucratic hellscape problem.
https://www.ourmidland.com/news/article/Wixom-Lake-may-be-drained-due-to-lack-of-funds-6945317.php
Do you know if Sanford lake was being kept 8 feet below normal level as it was supposed to until repairs could be completed?
https://pbs.twimg.com/media/EYa5SktWsAA_ESM?format=jpg&name=large
Looks like first dam to fail was Smallwood