To the OP's point, why would anyone stage an elaborate fire just to attempt to rescue only SOME of the kids? Weren't ALL of the kids in danger?
For the sake of argument ... Sometimes only a few children in a family are abused. Perhaps they were not able to rescue all of the children at risk?
Most people cant keep their mouths shut. It's human nature. How can ALL of these people be involved in an operation to abduct these kids yet nobody talked (including the kids) all the way to today?
Kidnapping would be a felony that, if I understand American law correctly, would carry a penalty.of life imprisonment. Aggravated cases of kidnapping could even lead to capital punishment: Burning down the house and nearly killing everybody might count.
Between that, and the knowledge that they would have been saving the children from a presumably terrible fate, I can see them staying quiet.
As for the children, outside perhaps of the very youngest, they would all have been happy to have been removed from a bad situation and disinterested in resuming contact with the family of birth that mistreated them so.
Nobody involved stepped up after the fact to collect the reward $$$?
None of the kids came forward after the fact because they miss their family?
Once the children were sufficiently far removed from their home town, they would just be dark-complexioned people of some presumably Latin background. They would not stand out.
As for the children, why would they miss the people who abused them so badly? In this reading, they did not make contact not because they were kept from making contact but because they did not want to make contact.
So all of the people involved with this "rescue" were willing to commit a crime (kidnapping/arson) and be part of a relatively dangerous operation (dangerous to the kids and the "perps") to rescue these kids when all they had to do was grab them when they were walking home/around town? Or even call the police/authorities?
Expecting that the authorities at this time would do anything about abuse, especially if it could be passed off as normal discipline, is optimistic.
Beyond that, yes, this plan carries huge risks for everyone, for everyone in the Sodder family who could easily have all burned up and for everyone involved in the plan. Presumably the people involved would have thought this would be the only way to save the children.
The other suggestions traditionally shared, that they children were abducted by someone and kept by some organization from freely contacting their family even as adults, are implausible. How can you get such powerful conspiracies to form, to do these things which would carry such terrible risks for them for no obvious benefit? How, for instance, would the interests of the Sicilian Mafia be served by holding these Sodder children virtually hostage without actually contacting the Sodders? If they had abducted his children, the fuss that he had maintained for decades could have blown them up? Hoover would love investigating a criminal case that would prove that the Mafia posed a threat to law-abiding Americans. Why would supporters of Mussolini, who had been executed by partisans eight months before, waste their energies tormenting a minor opponent in America in this ambiguous way? If either group actually had set the fire and kidnapped the children, considering the legal and other risks to them it would make the most sense to assume that they had been promptly killed. What reason would a corrupt West Virginia police force have to engage in this risky long game with the children?
The idea that the children had been rescued from their home, the fire set for purposes of camouflage, does explain a lot. It explains, most importantly, why the children lived yet failed to contact their family of birth: The children did not want to contact their family of birth for the most obvious reasons, hopefully having been moved into better homes. It would also give a plausible motive for people to get involved in such a complicated and risky plan: Presumably they thought this was the only way to secure the safety of the children, and were willing to take the risk in their name.
It goes without saying that no one at all, in any of the articles I have read over the years, has suggested that the Sodder family was anything but a normal family where the children were treated normally. There is no evidence that it was bad at all. There is absolutely no evidence that the Sodder household was so bad that presumably multiple people were willing to risk the lives of the children and their own lives pulling off such a risky plan. This proposal seems unmoored from the reality of the Sodders' lives.
I would suggest, though, that it is still the most obvious explanation for how the children could have lived well past the night of the fire. All of these children, save very possibly the youngest, were more than old enough to know who they were and where they came from. If they had normal experiences in their family and their home community, then even if they were told that their family was dead one of the five might plausibly have been expected to be interested in checking out their hometown at some point in the decades of life that they had. The idea of a multi-decade conspiracy by the people who abducted them to keep them from contacting the Sodders is unlikely, not only very difficult to operate in practice but hugely risky for them. What would be the payoff? If the children were removed from the home with their consent because their home was unsafe for them, that would at once provide a plausible motive for their abductors and a plausible reason for the children to avoid their family of birth.
If we reject this—something that I think we have to do because we have absolutely no evidence that the Sodder family was a normal loving family that would certainly provide these motives—then this leaves us without any plausible scenarios for the children being abducted that would also be compatible with them living well past the night of the abduction. If we do that, then unless someone can produce a plausible alternative this leaves us only with the possibility that the children died that night, most likely in the fire but just possibly by abductors who inflicted a terribly cruel ambiguous grief on the Sodders.