According to this story in the Wolverine (LINK), Rumeal Robinson will not be joining his 1989 teammates on Sunday as they're honored at the MSU game. Robinson apparently has a "prior engagement."
I thought that "prior engagement" might have been prison, but it turns out he was released in 2016. Considering his crimes (among other things, he swindled his mom out of her house), it would have been interesting to see the reaction among the crowd if he had shown up.
Speaking of the 1989 reunion, Sam Webb had several members of the team on his show today (including Terry Mills, Sean Higgins and Mark Hughes), and they told some great stories. The best (which we've heard before) was about Bo's speech to the team after Frieder was booted out. The way Bo went around the room and called out each player personally was awesome. ("Higgins, if I hear one more word about you wanting to transfer, you can bring the transfer paper to my desk and I'll sign it on the spot!")