CPS is responsible to investigate any circumstance that potentially poses a risk or a danger to a child. If CPS is convinced there is an ongoing risk of harm, they can remove your child from your home. IMO, CPS determined there was an ongoing risk for the children of JW/TW to remain unsupervised with the children and they were removed.
As far as I know, I don't believe that JW/TW ever requested CPS take custody of their children because they were worried for their safety and welfare after siblings Orin and Orson were abducted from the backyard -- as they alleged to police.
I don't ever recall the parents expressing concern that the children could have been abducted as a warning or for revenge against them for some prior bad deed. Nope -- I can't recall the parents feeling responsible here at all!