If the childfree dc dies their inheritance will go to their spouse (no blood relation) then to his blood relations. I'd want to sort my will so only my blood descendants would inherit. I don't think that's unreasonable. I've worked to provide for my family, including future DGC, not the family of spouses of my DC.
My parents, through making that decision, have now been left with no care in old age - we had always said that we would have both/either live with us as we have a large house with plenty of land and live in their supposed favourite place. We are also the only people who could afford to supoprt them financially in old age because we are the highest earners by far in my family. We were willing to do that so if they needed care - either homecare or care home - so they didn't have to sell their house to pay for it themselves....so my sister and her children, who are not in the same financial position as us, would have their inheritance.
They expected to make the decision to disinherit me because of a lack of grandchildren and for us to continue with our plans to care for them and pay for them. My sister also supported their decision to cut me out because, in her view, it meant that her children will inherit money from my parent's house sale as well as anything I left.
Sadly, for them, their selfish decisions have resulted in us withdrawing our offers of help. We have also changed our wills so that my husband's nieces and nephews are the only family to inherit anything from us. My parents will have to sell their house for any care home fees etc. My three nieces will receive an extra few thousand now I'm out of the will as most of my parents money is tied up in the house.
They will be worse off financially and, as we have decided to not bother with my family at all, have lost the financial help that we have given my sister and her children for the best part of a decade. Not to mention the relationship with us, though I guess as it shows my sister and her children are only interested in being propped up financially so no great loss to us.
All because people like you believe that FAAAAMILY is just blood and that the man who has been my partner both in life and business for 30 years, who has provided care for my father when he was going through cancer a few years ago, who has babysat for my sister many, many times when I couldn't and she had no one else, who took my mother shopping and to appointments and spent hours talking to her when my father had cancer....might just inherit my estate on the off chance I die before him.