The movie industry has realised that the encryption keys can be detected and removed. What they are now doing is copy protection during the authoring process. Unfortunately; most of the guides relating to movie authoring have been removed from sites like Doom9, Afterdawn, Digital Digest, etc.
I don’t have the article available to quote it. When the encryption keys are removed references to authoring files are removed. Some movies contain authoring to stop playing censored material to pass various country censorship laws. I have seen movies that were ripped and show alternative scenes in movies. Other movies, the ending cut off.
There are many bluray titles appearing on the market that do not contain a main movie m2ts. The movie is in sections and not in chronological order. Wall.E is a prime example. Do a virgin bluray rip of Wall.E and use ImgBurn to make an ISO file. The movie starts playing; it stalls, plays, loses audio and skips sections.
There are a number of bluray re-authoring programs on the market that are supposed to detect the encryption keys removal and re-author the bluray. Some work better than others. I gave up, I play bluray movies from a dedicated movie computer.