[MrDOS]

The format itself is patent-unencumbered. That doesn't mean I couldn't still write a non-free decoder and license it to Pioneer for use in their CDJs. Due to organizational inertia, I suspect that's what's going on here (e.g., they licensed a decoder from Fraunhofer or another commercial implementer twenty years ago, and have been using the same one since).

[immibis]

In this case, everyone at Pioneer knows their CDJs are used almost exclusively for commercial purposes, and perhaps they couldn't get away with lying about it in the fine print.