I think they could connect the pathway from Suess Landing, around the water side of Mythos, to the bridge that goes under Velicicoaster to the Wizarding World entrance. That would allow Mythos to remain untouched, except you would enter from the waterfront side and continue to walk around the park while they tear down Lost Continent.
The entire back part of the land could be fully rebuilt without affecting Mythos. Also they kind of need to do it this way to allow guests to walk around the entire park during construction.
Then, after the new land is built they can redirect traffic and redo the waterside of Mythos if needed.
Personally I want them to keep the food at Mythos but wouldn't mind if they redid the outside. It's cool but just looks bit dated.