It sounds like they aren't planning on building as far East as you've labeled here - although I wish they would, because the best and most logical connection point to Villains Land is through Fantasyland by passing Gaston's Tavern. The second best thematic point would be past The Haunted Mansion, which sounds like part of the plan, but in my dreams Villains wraps all the way behind Mansion and Small World over to Gaston's.
Build some sort of spooky Cave system if you must, Disney. Go for that indoor/permanent nighttime idea that's always been bandied about if that's what it takes to prevent the land from closing during the Fireworks. A Villains Land in MK without a connection to Fantasyland - especially when such a solid thematic connection point already exists - would be a misstep.