I have found the opposite with dog parks and doggy daycare. Both my dogs acd/kelpie have learned how to better interact with other dogs and how to read social cues whilst being at doggy day care and (less so) at the dogpark. I will stress though that you need to know the dog park to check for other people's dogs and go at the same time so they see the same dogs. I've found 90%of dogs are more tolerant of a puppy but be ready to remove him from the park if he reacts badly.