I got the served by 3 persons treatment as well. On both flights. Perhaps they mistook us for revenue passengers? On the outbound flight, the person preparing my meals even introduced herself. The person across the aisle from me was also on miles, and as far as I could tell, he received similar treatment. Also non-Japanese.
If anything, I think they do more with non-Japanese. From what I saw, the communication between Japanese is quicker - thus more streamlined. It took a little more time with us, with the slight language barrier using English (and my halting Japanese words), plus background stories etc.