My opinion is that it is EXTREMELY cruel to amputate their tail!! I cannot imagine doing this to an almost full grown Yorkie....no matter what the reason is! I can't speak for the dog, but I can speak from personal experience and when you have severe trauma to a main nerve(s) they are permanently damaged and, with me, VERY sensitive to even light touch. It's not fun and it even makes me jumpy and paranoid when someone is close to that particular spot....I imagine a Yorkie would feel the same way.....pain associated with touch.
I wish those that have Yorkies with full tails would love them just the way they are!!