I think the fact they are requesting a DNA test might give weight to their claim. Who would ask for one of these unless they do truely believe there is a possibility. The childs mother could of made these claims to both her parents and the child earlier on. Whose to know. I feel sorry for this child if he has believed all his life Michael was his Dad and he finds out he isn't. For his sake, I think a DNA test should be performed to determine parentage and allow this child (now adult) closure.
My husband and I have 4 biological and 3 adopted children that we have raised from birth. Although my husband and I have raised all of the children the same, our eldest adopted child does have questions about his birth parents, particularly as he has the possibility of 3 men being his Dad. His mother is no help in this area whatsoever. For his heritage/identity I hope that we can help him in finding out who this man is. To him, we will always be Mum and Dad, so there's no questions there in his mind. He just wants to know where and who he came from, and I think he has a right to.
Same goes for Prince Malachi. The test will put an end to any speculation and allow him either closure or a new beginning.