Hi! Welcome to YT, your puppy is very cute
.... I've never seen a Yorkshire terrier with such short hair as a puppy before. From the look of his current coat, it looks like it has great potential to get a little longer. Perhaps never floor length, but most definitely longer. I think as your pup gets older the hair will begin to grow out. I can't really say for sure, though!
I had a yorkshire terrier mix puppy once, that had short hair like that as a baby. I know you said your puppy is purebred, so it doesn't really relate.... but the hair length was the same. It took the puppy until it was one year old to have fluffier hair.
Either way, you have a cute pup
