Our society limits people’s scope of action to their lives. We ban post-death trusts, or at least do not give them the protection of the legal system. We do not allow the creation of corporations/organizations without a terminal human owner. We limit the ability of the past to control the present and future. No hands from beyond the grave.
Are we right to do so? I don’t know. Social questions are difficult. Every decisions spirals into a fractal of consequences and interactions, the tiniest change in initial circumstances creating a different fracture, different patterns and colours. (Not all effects are chaotic. Some things have predictable effects.)
Morally, I do not see why those who exist should have more rights than those who do not. Why the will of the living should matter more than that of the dead or unborn. Existence is morally arbitrary. The reasons we privilege it are practical, not pure.