Per Sam Webb on the Recruiting Round-up on WTKA (use iHeartRadio), and didn't see any update in the Isaac thread from last night. Webb says absolutely Isaac is interested in Michigan. He gained his release to 17 schools, one of which is Michigan (and includes several other unnamed B1G schools), and none of which are Notre Dame or Ohio State.
His guess is that M will talk to him and see if this interest is genuine, and if something happens it will happen quickly. There is too much risk to Michigan with Harris and Weber to have an extended courtship with Isaac as he debates a lot of schools, and then lose him. They already know he can play, given how close he was to coming here last time (obviously the coaches liked him then, presumably still do now). Said Michigan will say "lets' talk turkey", if you want in come on, otherwise they won't linger. He said Isaac was second on the depth chart at USC as he left.
Also for any that missed the update on the Mykhailiuk thread - Webb says probably not happening, don't bother learning his name.