Aye, indeed.

But maybe I don't want to leave my password behind because I'm weird that way or something, and instead I just want my account nuked.

Cryptographic proof of ownership by the dead guy + death certificate should allow for account nuking, without allowing for a third party to do something else with my account.

(Not that I'm worried about it, myself. In fact, I've found all of these dead man's switch/after-death automations pretty amusing every time I've seen them pop up in the past couple of decades.

I mean: When I'm dead, my HN/Google/whatever accounts will become idle, and I'm dead AF so I don't care if someone hacks the passwords some time later. It's a non-refundable one-way ticket for me.)