Did you read the article? It clearly states that the "species" is unstable, prone to health problems and has major reproductive issues. What do you expect is going to happen if they are in the wild?
French bulldogs have to be almost exclusively birthed by C-section, because their heads are so big, and the females typically need to be inseminated by artificial insemination, because the males have a very hard time mounting females.
But they're very popular and widespread.
[1] http://en.wikipedia.org/wiki/Tahltan_Bear_Dog [2] http://en.wikipedia.org/wiki/Category:Extinct_dog_breeds