My understanding is that Zach meant the U.S. National Title all along, not Olympic gold. He felt the need to clarify what he said, because it could've come across as disrespectful to the other U.S. top teams or ungrateful for his and Madi's previous bronze medals.
In my opinion it is not disrespectful to want a gold medal (olympic or national) of any team. But I don´t know, maybe someone told him something.