Sanders, once his campaign learns from their mistakes they can start winning again.
They seem eager not to learn any lessons. That's kind of the problem with his entire campaign, trying to repeat 2016 without moving forward with any of the lessons learned from that loss. Given what I've seen there's too many yes men running the show, pretending everything is going according to plan, to even try to fix the current course.
So yeah, Michigan is Biden's to take. Sanders will be competitive but won't win it.