I just today got an email notifying me that our flight down in May has changed off the Max 8 to a 738, along with the time change, with a very slight upgrade in seat assignment, closer to the front, but NOT in the extra leg room seats. I paid for just regular seats. Our return flight is still listed on the Max 8, but it looks like they are not going to be doing formal changes to schedule until February 23, so presumably at some point after then, we will be notified that our return flight has been changed.