Well, I can't directly answer your question however I don't think it would make much difference if you flew out and back with the dog or just had the dog fly alone.
I will say that our pup was Mr. Brave at 8 weeks and the fear period came later. I am going to say each dog is different. Is there something to make you believe the dog is currently going through some type of fear period?
People ship pups all the time, The breeder included, I wouldn't be overly concerned. Discuss your concerns with the breeder, they should be very knowledgable on the subject.