> It is in the context of being a historical fact.
And if someone chooses to have all of their work destroyed, then that is their history. In any case "public interest" outweighs a person's personal wishes only in very rare exceptions such as statesmanship. Here it clearly doesn't.
> Non sequitur. Adding a book to a bibliography does not change the content of the books that have come before.
Only in the same way that a later chapter in a book doesn't "change" the ones that came before. It changes how the previous works are perceived - art is all about perception.
> If I am a student writing a PhD dissertation about him I absolutely want every single fact I can get my hands on.
There's little reason to care about any unpublished books, because they cannot have had any influence. It's fine to be interested in them anyways, but mere interest of the living is not enough to excuse any of this.
But even if the person who wishes to have their works destroyed gave a completely nonsensical reason, their executors still would not have the right to go against it.
If people cannot expect to have their wishes honored, they will merely take more extreme measures to ensure they leave things behind to their liking. Nowadays that likely means encrypted drives and dead man's switches. But do we really have to go there? Can we maybe instead just expect society to behave honorably?
> Original sketches are extremely important in every subfield of history: from poetry to literature to music to painting.
The word "important" is doing a lot of heavy lifting here. It is very important to my daily commute that there be a highway from my front door going straight to my place of work, but I don't think it's going to happen.