John,
Nuforce has now updated their official upgrade/trade-in .pdf and they confirm your understanding.
I still don't understand the logic here, but it is of course their call.
On the positive side, I have just saved 4600 US$. 
Regards,
Bernard
My comment here covers two area:
1) Moving to other amps - if customers want to purchase another brand, so be it. We compete base on merit.
2) Upgrade or trade-in policy - it is priced for customers to stay within the same product line. That's why we have generous trade-in for P8 to P9, or if you stay with Ref 9 series, future upgrade cost a ridiculously low $400 for a brand new high-end amp module (don't argue about cost of parts, R&D is costly).
We plan to offer CMA capacitor board upgrade for the Ref 9V3SE. And you can bet that 2 or 3 years from now, there will be a V4 (it is getting harder and harder).
The 8.5" products are not going away. It is our equivalent of BMW 5 series whereas the 17" products are the 7 series.
When we buy back the products at 60% of the MSRP in credit for Ref 18, we have to refurbish them, and then sell them for bstock (80% MSRP). And take the risk of inventory sitting in the warehouse for long period of time.
I will look into the possibility of offering a higher trade-in credit.