I doubt all of England and all of Germany appreciates Welles as much as the Munich and London film centers, and conversely, these Welles films would not seem out of place at all in American film centers like Lincoln Center or the Museum of Modern Art. I think we might be cautious about lamenting the way "America" has treated Welles: in the past eighteen months, I've seen F FOR FAKE, THE STRANGER, TOUCH OF EVIL, and CONFIDENTIAL REPORT screened once or more in New York. His American films show up all the time on Turner Classic Movies. And in September, the Makor/Steinhardt Center will be screening a 35mm print of THE TRIAL several times.
I don't know if cinephilia in America is as widespread as it is in, say, Paris, or Tokyo, or wherever. But the packed houses I've witnessed for Nicholas Ray, Ernst Lubitsch, Robert Bresson, and Michelangelo Antonioni films seem to indicate that there's no special "problem" with appreciating a great artist "like Welles" in the US.
That said, I would be very surprised if I saw the rare/incomplete/suppressed Welles films shown to the public at a US film center. And we know the reasons for that. I'm thinking of how a video of FILMING 'OTHELLO' could be shown locally, just to spite Beatrice.