IF the breeder thought he was good enough to breed, he wouldn't sell to you - just to be blunt - or would do so with a contract that he maintain co-ownership, the dog be shown/proven in working arenas and that he be bred. If he's not doing those things and you're more comfortable neutering - neuter.
Even the best line dogs have litters that are not The Best. That's the way genetics work and most will hold onto the ones they want to breed themselves, or to known working or show homes. That isn't saying that the pups they sell are somehow 'bad', or defective, just that they only breed the very best of the very best, who PROVE themselves to be the best in either conformation or work (and send those dogs to homes that will be showing or working homes). The ones who go to 'pet' homes almost always do so with a contract that says you will neuter at some age/will not breed.
So no, you're not likely to have any issues with the breeder.