Breaking backward compatibility would be another issue if devices cannot be upgraded, some kind of planned obsolescence where you need to throw away your perfectly working device for no good reasons.
How does that work in practice though? Does it mean I cannot read recent blu-rays with older blu-ray players with the old key?
>Does it mean I cannot read recent blu-rays with older blu-ray players with the old key?
Yes, newer blurays may require a new player or a system update for your player in order to play if they require a newer security baseline than what you have.
What's the maximum time a DRM system worked before being completely broken? 2 years? 3 years? It'd be surprising that they did not anticipate that. But then again, I'm not sure why they would really care, they don't really make movies as far as I know.
How does that work in practice though? Does it mean I cannot read recent blu-rays with older blu-ray players with the old key?