This "encryption" was arguably never for any security anyway, just obfuscation.

Any crypto that prevents casual tinkering is enough to keep most companies from wasting resources on reverse engineering stuff.

Back in the day we wrote a simple byte-level nonce + delta obfuscator for a terrible Node-RED-like programming environment so that we could tick a "must not be human-readable" requirements checkbox.

If the cryptography, proper or not, has been written for DRM purposes, no legal department is going to permit digging into implementation details even with a ten feet pole.