I'll defer to anyone with more recent experience if I'm blowing smoke on this, but as an ex-aerospace engineer, I call that line of wordsmithing absolute BS.
Depressurization (at least they could spell it properly) typically RESULTS after a hull failure, window or door loss, but the only cause I can think of for a sudden and catastrophic break up of an aircraft is OVERPRESSURE.
Such as an explosive device going off.
(And don't even bother with "the lightning strike caused it" meme: Been in an aircraft that was struck by lightning and never caused an explosion, even when we were packing a load of bombs.)
From what I'm reading, your assessment of the cause of overpressure...seems increasingly likely.
Dunno about the motive, but the circumstantial evidence, the bomb threats, the devastating breakup, all point to a bomb.
The amount of tiptoeing around this smells.
All electronic systems simultaneously!