Whats more, studios more than likely do not have these films.
Archives do, if they exist at all.
I could go on, and on, and on with thousands of films. My point here is NO money is being made on the bulk of motion pictures ready to fall into the public domain in the 1920's. Commercial, specialty archives are ready to preserve these films if they can use them commercially through public domain. This is who should benefit from the extension. Not a bad deal if you can get it.