Well, it was inevitable. The last company within the state (HAP) has now decided that they are not going to be issuing policies for children only. For a while HAP and HealthPlus were trying to stay alive with regards to this provision of guaranteed issue coverage for child, but as you can see both gave up.
If you are in Michigan and looking for child only coverage, I would do one of two things. I would look at the MIChild coverage (keep in mind that program is based on income), and/or I would look at specific programs (if any) within your county.