I don't think they will ever bring big money over the price of non-chopped ones as they would be "chopped" and counterfeited.
I'm inclined to agree with your theory. Just as due diligence, has anyone done any comparisons with known 1875-CC MM placements? The point of chopmarks is a microcosm of the broader numismatic experience - coins are history, and chopmarks are an important happenstance in the history of this specific series. I don't observe Trade Dollars from other countries (Japan, Britain, etc.), but I suspect they each have their own chopmark aficionados.