My opinion is that the thought of adding another entrance has never even been brought up. Not that it would be so difficult to add one (explosives and all) but that adding one would require a large amount of re-thinking and re-design concerning that corner of the park. Although the area is not necessarily developed yet, I am sure there is a long range plan in place to do just that and that plan ties into so many other plans and infrastructure (and service areas and cast parking and emergency services and etc..)
On the other hand, I do keep an eye on the Google maps and my ear to the wall. When Disney rebuilt Buena Vista Dr. they rebuilt the bridge over the flood canal that runs from OKW southwest, and the new bridge is higher than the old one was. High enough for transportation to/from Disney Springs to eventually travel to Riviera Resort ? Yes, I know it's a stretch, reworking the flood system(s) and crossing the Bonnet Creek right-of-way. But I like playing the 'what if' game !!