I’d guess some of them would be pushing 35 by now so it’s a moot point, but Google didn’t immediately reveal anything about whether the embedded misssing children PSA-style shots (remember, it was the early '90s) had any practical effect.
I swear they found one of the teenagers. This was around the time that the video was airing in heavy rotation.
I seem to recall that one of the kids returned home on their own. The story as I remember it was that they didn’t think anyone cared enough about them to look for them after they ran away until they saw themselves featured in the video.
I think they found a few-then they rotated some of the missing photos periodically.