I would expect that with this change, pushing the movie back six months to a Dec 2018 release would happen. It might not, but i would not be surprised at all if it did.
They've still got almost a year till release. The big trick scheduling wise is building around the previous commitments of what is typically a very busy cast (Emilia Clarke with GoT commitments, Woody Harrelson works constantly, Donald Glover is like the most in demand dude in Hollywood right now). Six weeks of reshoots were built in, but if reports are true and the movie is as halfbaked as is being claimed they may need way more than that.