I don't find the explanation plausible, actually. If the aircraft had a sudden depressurization, and the pilots unconscious, it would stay straight and level u

I don't find the explanation plausible, actually. If the aircraft had a sudden depressurization, and the pilots unconscious, it would stay straight and level until out of fuel. If the aircraft transponder (ADS-B) and ACARS (Satelite) link was disabled by a blowout near the antenna, then other VHF radios would still function. If ALL those communications systems disabled with the crew conscious and the aircraft still flying they could activate handheld ELTs kept in the cockpit.