If your interpretation is correct, and I frankly don't know one way or the other what to believe about it, with the way you interpreted it, it will merely mean that until such time as things further change, we'll need to do what I was saying before and have federal law pistols with 16" barrels and an OAL under 26" Uzis, AKs, 10/22s, MAKs, maybe others, will be the way to go.
No more shot guns besides AOWs in cars if you're right, but it will be a new business opportunity for builders to make some money on Michigan specific rifle compliance crap.