Why are you limiting it to "after" the 2385? What about "before" the 2385?
Marantz's first receiver (way before the 2385) was an 18. It wasn't 18 wpc, or 118 or ???
Next was the 19...same thing as the 18.
So what you are saying is...Marantz didn't know how to add, then learned how, then forgot.
Focus on what you're getting and not what you're missing.