You're the breeder...your choice.
I can tell you that if I was rescuing or whatever, I'd take a Yorkie with a full tail. But I would most likely only go to a breeder for an AKC registered Yorkie. And if I paid full price, I would expect the tails be docked. I personally wouldn't pay too much for a purebred Yorkie who is so off standard... I like the docked look.