Not excusing the practice, but I’m pretty sure Boox products use a highly customized version of the android kernel to work better with eInk screens. It’s not as simple as just using the latest AOSP for them. Sadly, this also seems to be standard across all eInk Android tablets, though it looks like at least some Boox products use Android 12, while most of the space is stuck on Android 11.
I also pick this guy’s IRC