Sig glanced at us several times while we were there (sitting behind him) but he remained focused on Dawn who brought him to class and who is sitiing him for another week. That is actually why they encourage sits, so the dog learns to work and focus on different handlers. We also do group outings with the dogs and will pass them around for the same reasons.
When he does back to NY for his "college entrance exam" there will be two different trainers in the area who he has never worked with and part of the exam is to see if he will focus on them and what they are asking. If he goes into harnass training, he will also have a couple of different trainers over the 6 months, so he needs to understand when he is working, he focuses on his handler.
When he was "freed" last night he did come up to say hi with tail wagging and greeted us. And he was happy to see Bent and was wagging his tail and kissing him. I think he was happier to see Bentley than me!
I have seen videos of really excited reunions, but when I watch, it is usually the human who starts the excitement and the dog then follows. Personally, if he eventually guides, I want him to be very attached to his handler and am happy if I am just a distant memory.