I've posted on here before that given the state of technology, every single electronic keyboard instrument should have rudimentary arranger capability, such as an auto bass chord where a single note can trigger a full major chord and bass note. We're well past the point where it's a mechanical or electrical NECESSITY to press three or four keys and a pedal note.
Specifically, if Roland are out of the arranger market for good, they should imbue their MIDI controllers with Chord Intelligence and/or place their Chord Intelligence in the public domain so that it could be incorporated into tablet apps, etc. As a reminder Roland's system doesn't penalize you for playing all the notes. But it makes life much easier for those who never learned how to do so!
The 1 finger chord accompaniment came out in the 70s to make home organs easier to play, before moving onto the serious stuff, it is not new or unique to the arranger keyboard.
Bill