I still somewhat disagree. While I do agree that once I die I'll be beyond such concerns, that doesn't mean I should consider anything that happens after my death meaningless. You mention scandal that could threaten/harm them, but I think it's entirely reasonable to consider the "harm" that can come from simply ignoring the impact your secrets might have.

If you're really keeping a secret from your family, it's probably because you don't want them to know something about you... even if the secret coming out can no longer affect you, it would certainly have an impact on your family to discover that you had kept it from them all that time. Even if you can't feel the shame of it, your family and friends could still feel betrayed by this revelation. Sure, that would be "on them", but in reality it would be the direct result of something you did (kept a secret) without regard for what would eventually happen (you die and the secret would likely be discovered).

Now, to be clear, I'm not saying that such "in the event of my death" plans are an important thing to have in place. I'm just saying that there are plenty of secrets you keep for reasons besides shame or embarrassment, and that wanting your secrets to remain that way after death seems like a perfectly reasonable request, and making plans to handle them seems like a good and decent way to do so.

Granted, the examples in this thread were about kinky sex stuff, which is probably less of a "disrespectful shock" and more of an embarrassment, but I can think of plenty of examples where the same discovery could have a much larger impact. If someone is gay and doesn't want their family to know, it seems fine to me that they have a plan in place for a trusted friend to help maintain that illusion after death.