Receipt of engine performance data for several hours is compelling, it assumes serviceable electrical channels, serviceable data busses from wing to main equipment centrex serviceable ACARS VHF systems. If this is verified, it's a game changer.
As you say,
if it's verified. But I bet very shortly in this place subsequent the receipt of the data will become fact/an article of faith/a given, so to speak, and off we'll go again....until someone either confirms it or reins it in - such is the nature of speculation and this place.
Frankly most of the stuff coming from the authorities contains an "if" or a "may" (e.g. the primary radar track), whether those on the spot choose to report that, or whether we choose to register the caveat is another matter.
Despite all the debate I'm still of the opinion that this investigation is still at the "nobody's got a ****** clue" stage, which is very sad for the relatives.