Do not put this into your will. Leave a separate letter for your executor that has no legal effect and will not be a matter of public record. In it you can express guidance, concerns, potential pitfalls, your opinion of Joe Biden, etc. Putting specific things into your will handcuffs the executor. In this example, what if Person X is dead, incompetent, or refuses to deal with the issue? It is then going to take a court hearing and order to get this changed.