"But then all that died down and as far as casting was concerned it didn't really matter that I had been on Broadway"

Taye Diggs is referring to his experience as a Broadway actor. He is saying that after his time on Broadway, it didn't actually matter to casting directors that he had actually been on Broadway. This could imply that he was not getting the exact same acknowledgment or chances that he had when he was on Broadway. It might also imply that he was not getting the very same level of respect from casting directors as he had when he was on Broadway. This might be due to the reality that Broadway is a really competitive industry and it is tough to stand apart. It might likewise be due to the truth that Broadway is a very specific type of acting and it might not be applicable to other types of acting. Whatever the factor, it appears that Taye Diggs was not getting the exact same acknowledgment or chances that he had when he was on Broadway.