Great overview. Just Historical FYI: The Purple was proposed to be a parking lot and primary gateway into the promonade over Harbor. This would do exactly what you mentioned with an easy I5 access both north and south along with newly built surrounding hotels in support. This also allows access and drive foot traffic to garden walk that can connect along to Toy Story development of future DTD entertainment district to make it all flow together.View attachment 752802
They have the Toy Story Lot property, outlined in red, as well as enough land along Manchester and Clementine (and several of the hotels on Harbor), outlined in purple, that could be converted from on-grade parking to parking structures with direct access from the 5 freeway.. For reference, the practical area of DCA is outlined in yellow. All land currently owned by The Walt Disney Company.
I could envision current day DTD being absorbed into the parks themselves with DisneyForward expansion of the two gates remaining and conversion of all the bus transfer lots to the purple area much like how they handle Mickey+Friends structure and flow.
Problem is Anaheim killed that parking project along with the DTD hotel project -- then was resurrected with the VDH DVC and minor expansion of DTD and replaced with DisneyForward.