Hi Jannie,
I think that what happens is that some people get dogs that shed...period. And they like to think that the dog is blowing its puppy coat...while in reality, I think that if the pup is shedding much before 7 months, it is likely going to be a light shedder.
Dogs do lose their puppy coats around one year, give or take a few months.
Labradoodle breeding is not an exact science...which is why so many people have a problem with it...but until the breed standards are adopted and accepted, you will see a huge variety of coat quality and consistency. This is not to say that it is a bad thing...I have F1s, as do many others, and they have some of the most wonderful traits of Labradoodles...but most often they do shed. Next is the F1B (which I breed) where the Poodle is brought back into the mix again to produce a more consistent coat...still not precice though (I had one puppy that looked exactly like a Lab...and he did shed.) The multigen is a best choice for coat consistency...but you pay quite a bit more for that quality too...
That's why you see so many price differences, so many different breeders, so many different looks, and such a wide variety of coats...including the shedding and "blowing" of the puppy coat.