Tim,
"Has anybody ever heard directly or indirectly why Anschutz has not decided to thread it's 54 series action?"
Yes, we discussed this at length over dinner during the last shot show when they were in town. In short, no, we will not see a threaded action anytime soon. They have a handful of reasons for moving in a different direction at this time, but one that stuck out was they are in the business of making guns for the shooter, not the gunsmith.
As Joe pointed out, the company is now under the direction of the eldest son, Jochen Anschuetz, and he is a very sharp individual. I suspect that if they do make changes, it will be in close consultation with his father and his brother Uwe.