Hi there! Congratulations on your new puppy. I think that it is extremely intelligent of you to select a groomer (or at least start thinking about one) before you bring your baby home. I am by no means an expert BUT I have hear HORROR
stories--dogs have died while being dried in cages. Look, I'm sure that many people do it and I can't say they are wrong but I would NEVER ever go to a groomer that uses cage dryers. ESPECIALLY for yorkies which don't have an undercoat and are so small. They don't take long at all to dry. A few months ago there was thread that I still shudder when I think about it. It was a lady who posted about her friend's yorkie being badly burned in the cage dryer. The baby was in the hospital with extensive burns. I don't mean to scare you (well maybe I do to help you protect your little one) but please look into this. The comment the groomer made about using the cage so as not to have the dryer by their head is outrageous!! Of course they don't like it which is why most people/groomers use a human hairdryer on LOW heat several inches away from their face.
Your child is probably onto something. Grooming places are not supposed to smell. At least not any that I have visited. It is a very hard process to find a groomer. Once you find the right one you will need to be extremely specific about the haircut because every groomer has a different opinion about what a puppy cut is (assuming you go that route).
The good news is that I don't think you will have to get your new baby groomed until he is around 5 months----you could probably wait even longer. You have plenty of time to visit places. Good luck and I can't wait to see pictures.