As juicy a read as it would be I for one hope that the kids don't start writing tell-alls. Neither Kate nor Jon is above pitting the kids against the other parent. Kate intentionally does it among the kids too - singling kids out, clear favoritism, getting kids upset with each other by collective punishments, and making it known her attention/affection was given only under very specific circumstances. Jon probably did it more unintentionally with his horrendous fame-whoring in those years post separation. I can only imagine the psychological abuse that went on.
Speaking as someone who comes from large family with only a fraction of the dysfunction - it can already be very difficult for siblings in large families to relate to each other in healthy grown-up ways when they have developed patterns of behavior/interaction with each other while vying for attention/affection from parents who knowing use their need for attention/affection to try to control them rather than offering it without strings attached. There will for sure be siblings unable to cope with the abuse who will put on rose-colored glasses about Kate and/or Jon and will remain loyal to one or the other. Others siblings may be so bitter they are unable to find any redeeming memories of either parent. Some will fall in the middle and will recognize the good and bad in both but even those kids aren't going to appreciate the dirty laundry being aired out. One of these kids starts giving interviews or signing book deals and I don't see how the sibling relationships would ever recover.
I for one though am not so sure we'll ever see the tell-alls or exclusives. A LOT of shit can go down in the lives of 8 siblings. The threat of mutually assured destruction via exposure of the intimate details of people lives (that weren't ALREADY caught on camera or sold to online rags by their own freaking parents) will probably keep the kids from giving away all the goods. I also have a smidgen of a hope that Jon's past the highest point of his famewhorishness and might actually want to see the siblings get along together as adults and so he may advise them against spilling the beans.
Jon and Kate will reap what they've sown when it comes to their own relationship with each child ad they get older. But the fucking damage they've done BETWEEN the children that will affect their relationships with each other for the rest of their lives makes me want to vomit.