If it had been bought by a military or government concern, it would not have been an open test. The device would be on its way to a test lab right now, not deployment somewhere.
The whole “customer” thing looks like a scam that they’re trying to hint is some big deal in order to gain legitimacy. That coupled with the fact that paying customers will be the future functional proof.
Time will tell.
And where do you get the idea that anyone is saying it is being deployed? I assume the same thing you say above about going to a lab right now for further testing. The military doesn't deploy equipment without testing the heck out of it as a rule and this would be no different. That's why my conclusion in the article speaks of it as a 'prototype' for this intended purpose. ("prototype for field operations as a mobile heating system")
Good point. The Navy has been open with its rail gun tests. Why would it be so secretive about a space heater?