Are you entertaining the idea that Global Intelligence at Disney actually pulls some weight in terms of national security? I'm not going to get into the specifics of the departments responsibilities/knowledge, but if they know about a major security threat to the parks before the FBI does this country is in some serious trouble.
Yeah, they've got some good info about holes in park security procedures, but someone looking to cause some damage would be thoroughly disappointed during an interrogation. Frankly it would be a waste of time.
Regardless, terror attacks can happen ANYWHERE in the USA. Paris is a sickening example of such. Elaborate plots aren't quite as easy to get away with anymore. Enough damage can be caused, as I said earlier, in low-profile crowded areas anywhere in the USA.