I think that is what people are worried about. If Hoke expects the class to be 26, he expects there to be 8 scholarships opening up. I don't know exactly what the SOP is on renewing kids for fifth year of scholarships but it doesn't appear to be as questionable as some of the things the SEC does. Additionally, it might not be just the older guys. Maybe some of the younger players don't exactly see themselves fitting with the new offensive and defensive schemes, so they will transfer, but haven't done it yet. Also, Blue in South Bend provides a good possibility below: maybe the coaches don't think it will necessarily be a 26 man class, but are telling recruits, so kids don't feel the pressure to commit immediately. This way the coaches can focus on certain recruits and positions of need and not worry about some kids committing prematurely without evaluating the whole situation and then decommitting down the road.
FWIW. Michigan doesn't seem inclined to get re-involved.