This is a very interesting compilation of various approaches to the cryptographic time-lock problem. The Bitcoin idea is particularly enticing, even if impractical, since the idea of using the Bitcoin blockchain as a relatively tamper proof "timer" feels like something that could be made to work in practice.

One gap though is that the opening example is the idea of creating an insurance file that is publicly decryptable at a certain date if a particular real-world condition exists, like the file's author being kidnapped or whatever. But to make that work in practice you need not just time-lock encryption, but resetable time-lock encryption where it's possible to delay the release of the time-lock if that condition has not been met. I can see why the examples don't tackle that since even the basic problem seems unsolved, much less a tunable version of it, but it's a very interesting thought exercise.