I'm not at all in the field, but that doesn't match what I got from the Nature abstract. I didn't see anything describing the mechanism as "giving the antibodies another target". What I read is that the introduced MOG caused regulatory T cells to retrain the immune system to stop attacking MOG.

They do bring up the multiple target problem. The glint of hope for that involves "bystander suppression", which they found some evidence for happening, but I don't really understand what that is.