LOL, so they’re selling their 320kbps database as 256kbps, maybe they’ll come out with something “even better” later and give us what we already had with GPM. 
Anyway, the funny thing about all this is how their top-tier encoding for the public-video form of the songs is actually in 160kbps-limited VBR Opus, which allows some pretty damn amazing quality if you upload a lossless/uncompromised original, if I judge by this gem I recently found: https://www.youtube.com/watch?v=63TNghYjK1U
Download the Opus audio with
youtube-dl -x https://www.youtube.com/watch?v=63TNghYjK1U
and check out the spectrogram in Audacity: not a single sign of lowpass filtering anywhere below 20 kHz. That is something you just do not find on YouTube normally.