First sentence of my post, for this very reason – they own the franchise, after all. The law may also change the other way but that’s very unlikely to happen in the US within 50 years.

I wonder if they could develop a system of draconian DRM (only their own theatres with metal detectors, personalized online streams…) and mildly edit movies every few decades so that they can destroy the original and effectively renew copyright. The gaming industry’s always-online DRM makes nuking a release possible but copyright lasts for about 20 console generations so they don’t even have to do that.