People of smaller stature want to be called "Little People". Why not just call dimunitive yorkies "Little Yorkies"? After all, that is what they are...
I despise the word 'teacup' because to me it hints of 'toy-like' as in play toy, not toy breed. And it's very deceptive. Most small breed pups can fit in a teacup at some point.
If someone wants to describe their dog as smaller then just say SMALLER than average!
I have a smaller than average Chi, Figgy. When people see him, they squeal "Ooooh a teacup!".....I politely say "He's just small".
Most say it without any knowlege of the marketing ploy that it is. They're just relying on what they've heard.
