A breed like the otterhound, which doesn't have a proper job anymore, is large, smelly and can't be carried about in a Prada handbag, so is unlikely to even be recognised by the sector of the dog-buying public that wants a chihuahua; nor are you likely to get very far using it to try and rob an off-licence, so that's another sector gone.
If there is a core of the breed remaining, it can be brought back, but what, realistically, for?
The KC is only concerned with pedigrees and showing dogs and the income from registration which in the public's eyes is a guarantee of quality and thus helps breeders sell their puppies. They're only grudgingly concerned with "welfare" and that only recently. Popular dog breeds earn them money from registration and such, so it's not in the KC's interest to discourage breeding of any breed, rare or otherwise.
Personally I'd be more concerned with over-breeding, regardless of the origin of the dogs concerned. 43% of ALL registered Afghans ended up in breed rescue? That's an appalling statistic! Add in the ones that went to "general" rescue and the ones that were sold privately so probably slip through the net and you'd have to ask yourself why almost half the dogs bred ended up discarded. Is there an issue in the breed that's resulting in this? Poor temperament or health? Were as many bred and sold the next year? There will be the usual reasons for parting with a dog, relationship breakdown, loss of job, etc... but not 43% of them. That's frightening.
The article also specifically mentions huskies, a breed quite often in rescue (at least in my neck of the woods). They're appealing pups and stunning adults. But they're hard work, for Joe Average Dog-Buyer and his family. It's all very well saying such-and-such a breed should be more popular instead, but often they're breeds which don't have a logical purpose left or which are too much work for what is by some margin a "pet dog" market. People want these "designer" dogs now, the crossbreeds. It's just fashion, and will change again soon enough.
When half the non-dog owning public is crying out for the restriction or banning of bull terriers of one sort or another, and the current anti-dog climate, I think the KC will be hard put to find anyone outside the breeds themselves who cares about rare breeds.