Hi, Linda. It would be repeated on each profile where the profile is a child whose parent is directly in the DNA inheritance chain being described. For example, if you have evidence on your patrilineal line going up to the 2g-grandparents you share with another person who is DNA tested, you would add a confirmation statement to your profile, your father's profile, your paternal grandfather's profile, his father's profile, and then ultimately to both of those 2g-grandparents.
This Help page has an illustration of the confirmation status correctly being placed on all individuals for a 3rd cousin relationship.
Note, however, that the WikiTree guidelines allow the Most Recent Common Ancestors to be marked "Confirmed with DNA" only up to the 3rd cousin relationship, so 2g-grandparents. For 3C1R and beyond, where WikiTree requires autosomal triangulation, the MRCA is not marked as confirmed.