It's pretty useless, probably. I've read a couple of interviews with family members of the captured soldiers (for example, ¹). They don't seem to have any idea where those soldiers are and have no way to communicate with them. Although it may all be lies in an attempt to lessen their guilt, considering the rest of her speech ("he didn't know where he was going, he didn't do anything, those bad Ukrainians for taking him prisoner").
¹ https://novayagazeta.ru/articles/2022/02/27/ia-ne-schitaiu-c...