In terms of courses the Epcot to MK portion should be pretty much the same.
Yeah, I wouldn't expect any changes until well after that. The first 7 miles or so are pretty set in stone since they need to clear MK by park open. Unless they try to add an out and back by the fire dept, but that messes up the one way road over there. Depending on how much needs to be made up from DHS closures, I'd anticipate maybe seeing a longer out and back over by the tree farm, more loops through WWoS (Is that even possible?) or maybe some how adding an out and back over that way as well. The first 7 miles, and the last 5/6 are pretty much a lock, it's the half in the middle that could shift some.