Q: If a person has been received into the Catholic Church, do they continue to be dismissed with catechumens?
A: No. In fact, the dismissal at mass was designed for unbaptized catechumens, not for validly baptized Christians. The dismissal is optional. In some parishes, no one is dismissed; in others, the catechumens; in others the baptized Christians preparing for reception join in the dismissal. But once the person has been received into the Catholic Church, the person is a Catholic.