Earlier quoted context omitted.
True for Widevine L3, which is what the article is talking about. Not true in general, and not true for L2 or L1.
I'd argue the same goes for L1 and L2. But the obscurity is provided by the silicon packaging process. Would be nice to crowdfund a lab to break these hardware backed treachery schemes.
When you say “security through obscurity” there’s a certain understanding that we’re drawing a line between implementation secrecy (obscurity / obfuscation) and key secrecy. If we extend the word “obscurity” to include the notion of physical security, I think we’ve gone too far—even if physical security is just the physical security of a secret embedded in silicon that you have physical access to (because it is super difficult to recover secrets from silicon).