I believe the “reports” were in regards to his untimely end, that he had a dead man’s switch.
The nature of a dead man’s switch is that unless the person in question does something affirmative to confirm his state of well-being, something is triggered. In this case, if Assange could not communicate via internet, he would be unable to, for example, enter a code that would deactivate the dead man’s switch. He could be very much alive, and the switch would be activated.