There is no mystery about this, it is all well documented. There have been numerous examples of this, particularly for the pre-1948 movies. At one time, Warners had sold their pre-1948 films. They got them back. Paramount sold its pre-1948 library to Universal, which still owns most of it. MGM bought United Artists after the Heaven's Gate disaster. And so on, tons of interesting examples. Historically, people have always underestimated the value and importance of their collections. Many film companies are neglecting them today. Warners has done a really fine job with these collections. I doubt that the current MGM company could have done as well. It is no surprise that other groups are now leasing their titles to Warners for release. I rejoice in this. BTW: Jack Warner was long gone from the company when these things happened, so he is not personally responsible for the RKO or MGM acquisitions.