Long coat is a recessive, so for the puppies to have it the dam would also have to carry a recessive gene for long coat. If she does, there should be some long coat puppies. If she does not, there won't be any long coat puppies even though the sire is a long coat.
It's usually pretty obvious which pups are long coats by 3-4 weeks old. They start developing extra tufts of hair on their feet and heads, and their face often has an odd hair pattern to it that looks much like a schnauzer. If you can post close up photos of the individual pups we can probably give you a good idea of who is a long coat and who isn't.