I personally have no idea. They did mention they were only demolishing a portion of the building in a press release, which we all assumed meant they were only keeping a wall in order to call the new attraction a "renovation".
Maybe they really are keeping some of it in order to have a smaller build time. I have no clue.
And, I'll put the disclaimer on now, until we get an announcement this still is just a rumor. I could be dead wrong.