Writers don’t only write to be read.

Maybe he wrote them as practice. Maybe he wrote them to experiment with a new style. Maybe he wrote them to explore his thoughts and feelings. Who knows.

It does appear that he was okay with these things being published, but in the general case it’s not true that someone writing means they want or intend it to be published or even read.

He should have put in his will and testament that all unfinished drafts should be destroyed. I don't believe it is possible to will property to people but put indefinite restrictions on legal usage of the property. I forget the exact term, but the restriction was put in place so that you don't get into a situation where estates are confined to operate in the manner that a long-dead great-great-great-great grandfather specified in their will, in contravention of the wishes of the current property owners who may have not even been alive when the will was written.

Perhaps you're thinking of "mortmain", a nice English/French word:

https://en.wikipedia.org/wiki/Mortmain https://en.wikipedia.org/wiki/Rule_against_perpetuities

There's also the expression "dead hand", but that may also refer to a Soviet strategic defence system, which has also been referred to as "hand from coffin", which is certainly more fun than the official name.

Yes, but you may change your minde after writting it. Sometime you write something, and it's not what you think it would have been, and you don't want people to read it anymore.