I don't know. He never talked about a captivity switch.
Perhaps he is an object lesson that one should create a "switch escalator".
Perhaps a dead man's switch used in captivity could also potentially make captivity worse and remove what last remnants of hope he has. I suspect if he pulled the switch now then a lot of the sympathy he got for exposing a war crime might go out the window.
The purpose of a dead-man switch is that an action automatically happens, if a person cannot trigger that action themselves anymore. This is not required in any kind of normal captivity, where the captured still can talk to lawyers and other visitors. So, frankly, if Assange is not using the leverage (using in the sense of using it as a threat) my best explanation so far is that he does not have any (at least not anything substantial enough). But I am open to be convinced otherwise.
There are still lots of angry articles about how it will PUT LIVES AT RISK if it is unencrypted.
The powers that be appear to be walking a tightrope between not exposing their own assets and trying to make an example out of people who expose war crimes while trying not to put lives at risk.
