I agree very much that it's no coincidence that these boys of the same age all disappeared. However-I doubt very much that any of them lived to adulthood unfortunately. For one reason-I think that at some point, 3 or more strong young men could have overtaken their captor and escaped. In my opinion, they were most likely sexually abused and killed rather quickly. People are sick.
I'm not certain, but am inclined to agree. The only case I recall where an abuser abducted multiple boys and kept them was in the case of Michael Devlin, who kidnapped Shawn Hornbeck and kept him captive for 5 years. It all fell apart after Devlin was caught kidnapping another boy.
It seems someone might be able to keep 1 child captive a while with threats and isolation, but not more. Odds are, the situation ends tragically with the child being abducted, abused and killed within a fairly short period of time. The creep then goes quiet for a while before trying it again.