You are correct, Tidal decided not to continue on Roku. I am no longer a Roku user, too far as I prefer the Roku user interface. But once I bought a new latest gen AppleTV it was like an upgrade to to my stereo system, music sounded better from Tidal via AppleTV than it did on the Roku. Took a few months to get use to the Apple Remote and sensitive touch pad, but I not stream via AppleTV.
Maybe the next generation of Rokus will be good enough sound wise to lure Tidal back to Roku, as a superior user interface and remote, plus remote finder, for for the foreseeable future I am now a AppleTV user. Roku is still hooked up, and can be used, but I just don’t it anymore.