There were LOTS of folks excited for Rivers of Light this summer and up until the week before it was on go to open. Then with virtually no notice, oops we have a problem. I don't think anyone should book a trip around this land, you really can only depend on what is open. Even if Disney says something will happen, doesn't mean it will until it actually does.
Not saying it won't open fully or partially in the spring but we have no idea if it will open on time no matter what anyone says. ROL proved that, and other Disney in-house plans of late have not gone as planned. It's the new reality.