For what it's worth....
 
I have nothing bad to say about MF ferrets either, though I could say
plenty bad about their FOOD....but that's a different topic.
 
We have eight MF ferrets, all under four years old, and not a single one
is a standard sable.  We picked out exactly one of these - the others
came to us from shelters, private surrenders, and "can't sells" from the
pet store.  The closest we have to a standard sable are a tiny black self
girl, and a "sandy" or champagne sable.
 
On the other hand, we have two blazes who show none of the other WS
traits, and a deaf panda - an odd little boy who was very sick at a young
age and still retains sort of a "kittish" shape at a year old.  (Never
mind that he's now one of the heaviest we have....)
 
Ironically, the one standard sable we had (also MF) contracted juvenile
lymphoma and died at a year old.
 
I just got back from the pet store we usually use, and they have only two
blazes in their cage right now.  They were asleep and I didn't play with
them, so I have no idea if they were deaf or otherwise WS.  (It's easy to
resist playing with pet store ferrets - just keep telling yourself you
might carry a disease home - or that you might carry a disease FROM home
TO them!  <g>) We regularly see many fancies go through that store.
These are all MF.
 
So, from my small and statistically invalid sampling, it would sure
appear that there are still plenty of fancy genes in the MF stock.
Whether that's deliberate or accidental, I can't even begin to speculate.
 
FWIW, we also have two from unknown origins.  Both are even fancier than
the MFs.  One is a dark silver with a tan-beige undercoat.  The other is
pretty much a chocolate sable on his front half, but fades to a
salt-and-pepper silver on his rear half.
 
roger & the wolverine wannabees
missing bear
[Posted in FML issue 4065]