Nah. Walt Disney World, Universal entertainment venues and parks are ALL In the same county (Orange County). Parts of Walt Disney World however are in Osceola County. (All Star Resorts, Celebration, Wide World of Sports I think). Walt Disney World and City of Orlando have no real financial ties other than naming rights for things honestly. Orange County and City of Orlando won't have a problem with Universals new land as it is no different than the famous tourist trap International Drive going into both City of Orlando and Orange County.
I don't know about that second busiest intersection unless that includes pedestrian foot traffic on a daily basis AND The cars funneling on and off of I4 since that technically is super close to International Drive intersection, in which I could see the argument. I can think of 2 more Sand Lake Road intersections that are far busier vehicle wise, so for some reason i feel like that includes the I-4 exits and entrances being that they are not too far away.
Anyhow, There are plans to make Sand Lake Road better flowing as it is the only parallel access to the 528 West of the Airport into hear of tourist district. They have already started East of International Drive on Sand Lake Road. The Sand Lake I-4/Sand Lake International Drive/ Sand Lake Turkey Lake Road interchange should be starting in a few years.