Our last day at MK will be 11/12 and I'm hoping that there will be soft openings that day!
I've been googling this same question and some have said that early openings are more likely if it's a long refurb (and in this case it's about 4 months, so pretty long I think?). Rocking' Rollercoaster will also be closed for most of our visit, but I'm hoping we get lucky and get to ride both.
Another factor from what I've read is that Disney needs to schedule CM's in advance before being able to open the ride, so they need a few weeks notice. So they need a pretty good idea that they are ahead of schedule, a few weeks out.