I believe there are problems creating trusts or bequeathing assets to people who have not been born yet. Similarly for financial instruments (such as a promissory notes) which need to be made out to extant persons. Could this be an area meriting attention?
Whether retroactive paper could be established somehow for one's own benefit is an interesting point. Some of these things go stale after a while, some do not. Assets for the use generations not yet born is one area addressed by Nehemiah – including which spouses of those unborn should be excluded. This is perhaps where to look for guidance on the topic.
NEHEMIAH 10 click internal link for chapter-by-chapter reading