Yep everyone has basically said it! A yorkie is a yorkie!
Teacup is often a term used to sell yorkies for more money....
There are some yorkies that get to be like 15 lbs and stuff (some on here even!) and they are still just a yorkie. Same name as the little two pounders!
But we just have to accept that people use the word "teacup" and "tiny" and "toy" and "pocket" and other silly names. They dont know better but now you do!
Your little pup is sooooo cute