The DoD obviously has a need to message with people who don't have access to their hardware. Signal can basically do this on its own if you link a Signal account to an Internet-connected PC and back up those messages, I don't see why you would want a third party app involved.
It seems likely to me that this was the "whole point of Signal+TeleMessage" and then in addition to being a bad solution, it got misused for communications that shouldn't have left the DoD's networks anyway.
It seems likely to me that this was the "whole point of Signal+TeleMessage" and then in addition to being a bad solution, it got misused for communications that shouldn't have left the DoD's networks anyway.