We have the California park, I think expanding it out to include a park that brings to life some of the USA's other history from across the land would be awesome. It would open the park up for some amazing possibilities for imagination in newly designed attractions that don't necessarily have to be movie-based, but it would also be a great opportunity to bring something didactic back into the parks rather than just passive thrills.
The only thing that could bring about a question regarding a park that celebrates Americana is that much of Disneyland already does that.
I still think it would be better than a Star Wars or Marvel park. But then again, that's personal taste on my part.
When I heard news of that park in Virginia that they had thought about at one time, I thought that would be an interesting park to visit. So I'd have no prob with them doing something like that in Anaheim.