My Ematic Jetstream 4K Ultra told me that an update was available, and in the notes it says "Android 9". It's been happily running Android 8 this whole time, and I haven't had any complaints about it. It's updating as I type this, so we'll see if Ematic handles this better than Xiaomi did with the MiBox S.
Mine won't update, I've tried every trick even a factory reset, but it says it's up to date when I check and still running on Android 8. Can anyone help me :(