Nothing has been made public other than Andrew being Chief Engineer. So my assumption could be a Mojoism but then again, Mojo doesn't like to wrongly assume anything.
I do think the vast majority of the Bryston gear is of a higher caliber than Axiom's - including some speaker models. The T models are a higher caliber. I don't think the T subs are any different than Axiom's. The A models are no different than Axiom's. Of course there's a 20 year warranty and buying through dealers.
You are very right that Axiom is much higher value particularly when you factor in loyalty, trade-ins and deals. But all of that may be coming to the Bryston lines also. For example, Bryston is now accepting trade-ins through dealers for the 4B.