They most certainly do. A quick online search returns "NexGuard" as the used watermarking technology, at least in 2018. Edit: it's actually mentioned in a comm

They most certainly do. A quick online search returns "NexGuard" as the used watermarking technology, at least in 2018. Edit: it's actually mentioned in a comment not far from here (https://www.kaleidescape.com/news/kaleidescape-taps-nexguard-to-protect-pristine-content-in-early-window-for-home-entertainment/ https://www.kaleidescape.com/news/kaleidescape-taps-nexguard...)