There is an older lifetime addict that my daughter's knows whose grandparents/ parents established a modest trust fund for him because they knew, given the opportunity, he would blow it all at once. So now he has enough money to keep a crummy roof over his head and junk in his veins and has not worked in 25 years. In effect, they enabled from the grave.
I read a story about parents who set up a trust fund and made their son's access to it, conditional on periodic drug testing. It struck me as trying to control someone, from the grave.
Willing funds to a worthy cause instead of family often makes sense, regardless of addiction, or not.