I'm surprised they can predict that with accuracy. I know nothing about toys as I am looking on the opposite end, Standards and I do not care about how big or small. When I got my last dog there were 3 females available and I did not pick one because she was much smaller and whinnier (not that they always go together). The breeder said that sometimes a dog is the runt because it was conceived later not because it will be smaller since dogs often have more than one mating over the course of several days (or at least standards do, no idea about toys). My puppy was bigger than the other two, much bigger than the runty one. While I did not meet the others as adults, mine turned out to be on the small average side for a standard even though she was big at 8 weeks.
Also, is anyone at your company really going to be weighing your dog? Can anyone who is not a toy breeder tell the difference between a 4lb and 5lb dog? I have no idea simply asking. I would think the main thing is that it can stay in the carrier and be small enough to take on a plane and be relatively inconspicous and I think all dogs under a certain weight can do that but again I am not a toy person. I would think temperment would be more important, if I worked at a company and did not like dogs, it would be more important to me that my co worker have a quiet non yappy well behaved dog that likes being carried around than that it meet a certain weight class