In most states, to completely disinherit a child in a will, parents have to mention the child and specifically disinherit him or her. Otherwise, it is presumed that the child was left out by mistake. Tennessee has an exception to the rule.
J. Don Brock, the late CEO of Astec Industries, wrote many wills over the years. He executed new wills in 1994, 1998, 2006, 2012 and 2013. His first three wills all did different things with regard to his five adopted children.
They were given various amounts of money or cut out from receiving anything in the different wills. The last two wills did not mention the adopted children at all. They claim that was done by their stepmother, in order to preserve the assets of Astec Industries for herself.
The children filed a lawsuit against the estate, but lost in the lower courts. The Supreme Court of Tennessee has now agreed to hear their case, according to the Times Free Press in "Tennessee Supreme Court agrees to hear J. Don Brock estate challenge."
The main issue in this case is a 110-year-old decision by the Supreme Court of Tennessee that created what is known as the Cowan Rule. It limits the ability of potential heirs to challenge a will, if they were not mentioned in the previous will.
The adopted children lost in the lower courts because they were not mentioned in the 2012 will. The rule makes some sense.
Merely having the 2013 will ruled invalid would not create an inheritance for the children, since it would just validate the 2012 will, unless it is also successfully challenged.
However, this is not how other states handle disinherited children.
In other states, it is presumed that if a child is not mentioned in a will at all, it was a mistake and the child can challenge the estate, regardless of what an older will might state.
Reference: Times Free Press (March 21, 2017) "Tennessee Supreme Court agrees to hear J. Don Brock estate challenge."