But no matter when the Yamaha reaches the Audya's price point, it's guitar parts won't drop out or change on dim/sus/aug chords...

Street price will be the determining factor. If what we hear is true, at least Yamaha dealers have a fair bit of leeway to play with the margin. It has been made obvious that Ketron dealers have nowhere near the leeway to play with the street price... margins are slimmer, hence less wiggle room.