it is a question I asked myself. On the other hand, it is the kind of piece that we won't hear about anymore and it is a shame that only 7 pieces are made, knowing what mechanical marvel it is.
The 175th will remain to have a very specific more valuable casework.
Time will tell if it should have remained unique (7 pieces) or not. I must say I don't have a fixed opinion here.
As for the movement issue, I must say I don't think I agree with you.
First, because there is a moment when, if you have plenty of them in nearly every possible combinations, it is not necessary to make even more. patek has so much auto or manual calibers, in every king of chronos style, Minute Repeaters, QPs, square calibers, Split etc... It is huge.
All Patek movements are in-house today and well finished, quite big size (except the 215 manual), super accurate and reliable...
I know high-end brands which are still late in that field and trying to catch up so this let me think that Patek is certainly not late on the matter.
This being said, as the 31-260 is already available, it would have been nice to see it in a new reference though.
Thanks for your input!
Cheers, Mark