OP, I agree with what Swing said about trust.. no one gets richer though divorce and perhaps he has lost out financially having broken up with his first wife.
I also agree with your sentiment and that of Aroundtheworld that I wouldn't want my husband to treat my child differently at the point of his death in the sense that since he took me as wife (and as I took him as husband) we became joint, with a coalition on providing for and caring for the children, whilst all the time respecting the natural priority of biological bond. But we joined in marriage and share everything.
Magda asked about my kids and steps ages when we got together : they were 7yrs thru to 17.
Our back up plan on death of one of us was that the surviving spouse would offer continued housing and parenting if the child(ren) wanted it, with open and kind access to ex partners. Chances were they would have (or would still) want this! The ex's put on a good show but they currently won't have the kids any where near half of the time. Money would be tight but the mortgage (our lives) are insured so there'd be a far lower living costs at home.
Husband jokes of course how much better off financially I am with him dying sooner rather than later! He trots this out every time he finds a sewing needle on the bed/ a skateboard in the hall / something mouldy in the fridge.
Bottom line, in my case, the surviving spouse (which statistically will be me though you never know) might have to downsize.
And Magda I have also seen adult entitlement and my husband and I would hate to think our own children (when adult) could be this way!!
In our social circle, a retired lady who's late husband willed her the right to stay in the house or to get interest in the investment, until death, and therefore his adult children should wait til she passed, was harassed into a sale and settlement because the kids felt entitled, needed it 'now' and wouldn't wait. For her own health, she had to sever ties after a barrage of legal battling because it wasn't worth ruining her life's over.
My own husband saw this and would hate to have that awfulness, and also recognises it would severely STUNT my/ his life experience and trap us if there are conditions on keeping the house. His children won't inherit from him, I will. Nor will mine, from me. Sounds harsh. But they can expect our marriage to truly stand for something, and expect no inheritance and anything they get will be a bonus.
Lord knows what influences will be upon our children when the time comes. Some might be rich, others struggling. When all the children are grown, the children need to make their own ways in the world, and we will help them as much as we can, but they can't count on money.
Conversely, we have raised them to think that probably, they will need to support us when we are old or bereaved, like we do our elders!! Mum/Dad StepMum/StepDad asks - "please fix the computer, help me buy a new fridge, take me on a trip"...
The way I like it;
Loved and trusted spouses inherit.
Have life insurance.
Treat adult children the same on death.
In life, help the more needy.
Make everyone know they are loved equally.