Speculation on children. How the most humane point of the "peace" plan can play against Ukraine

The American "peace plan" contains a clause on "family reunification." At first glance, it seems that this is a chance to bring home Ukrainian citizens separated by the war or abducted by the Russians – adults and children. This year alone, more than 3,000 Ukrainians confirmed the fact of being in Russian captivity, and the total number of people known to have been in captivity during the war has long since exceeded 16,000. No one knows the exact number.

If this program is exclusively humanitarian, why is an "all-for-all" exchange of civilians still impossible, and how can Russia use it to legalize traitors?