It is in the Precepts of the Church where we find that all of the baptized are required to confess their sins when in the state of serious sin, before receiving any other Sacraments, apart from (under certain circumstances) the Anointing of the Sick.
It would be extremely foolish to assume that an adult, baptized in infancy, never committed any serious sin in his whole life, not even as a rebellious teenager. Therefore, before being admitted to the Sacraments of Initiation, it would be prudent to recommend to them strongly to make use of the Sacrament of Reconciliation, and to ensure that they are well-trained on how to do this.