Well, it is and will remain a general problem that technology in home theater moves somewhat faster than in the area of analog amplification.
That's what Bryston tried to address with the concept of the SP-1 that was upgradable to a higher degree than most of the pre/pros out there. Even companies that applied a fully modular approach with a bus system - possibly at the cost of sound performance - aren't able to cover all changes with an easy and economic upgrade.
Therefore, it is always dangerous to promise upgradability. If you do and fail to honor your promise, your reputation suffers. If you do offer an upgrade, it has to be somewhat attractive to your customers and even your distributors and dealers might want to have their cut in the upgrade process. To keep everybody happy and make an approriate margin yourself seems very hard to me, since I assume that the margin at Bryston products isn't like the margin let's say on Intel chips, where production cost is the least of the problems - only how to grab more of the consumer surplus. (or how would you interpret the fact that they criple some chips to lower the performance to sell them cheaper - they could - maybe at lower cost - sell them uncripled at a lower price but people willing to spend more would get what they want cheaper, thus realize a consumer surplus).
I don't envy James and the Bryston management as a whole having to make a decision that serves the customers and therefore Bryston...!
Cheers!
Markus