They are lowering expectations already....
My guess is we will have to wait at least year to know anything, even though they already have readings from both the CVR and FDR....
The article you linked does not support your speculation that expectations are being lowered or that we won't know anything for a year.
Some key quotes are the following:
However, the report to the International Civil Aviation Organization (ICAO) – a United Nations body – is likely to only contain basic facts garnered by investigators, according to air accident specialists, and not analyses and conclusions on why the Boeing 737-800 plunged from a cruising altitude.
The report would be based on verified information available at the time of writing, including speed, altitude, radar information and voice communication with air traffic control, Joe Hattley, a retired aircraft accident investigator at the Australian Transport Safety Bureau, said.
“The essential thing about a preliminary report is that it has no analysis, no findings, no conclusions, but there may be things like safety recommendations,” he explained..
If you have read preliminary reports from other crashes, you will see that Mr. Hattley's description is accurate. For example, consider the Germanwings 9525 murders. The ADS-B data included changes in the commanded altitude to below ground level. The voice recorder was found the next day in good condition. The data recorder was found about a week later. Criminal investigators had within a week found the co-pilot's computer had searches related to suicide. Yet although the criminal
investigators were sharing many of these details and the case seemed very clear, the accident
investigators did not release the preliminary report until 6 weeks after the crash.
When they did, exactly as suggested by Mr. Hattley, the Germanwings 9525 Preliminary Report was limited to basic facts, not analyses or conclusions.https://bea.aero/docspa/2015/d-px150324 ... 324.en.pdf
They stated, for example, that the pilot had left the cockpit while the co-pilot remained, the altitude selection was changed to a height below ground level, and that the pilot tried to re-enter the cockpit and numerous times tried to communicate with the co-pilot, in addition to the fact that the co-pilot had previously been treated for mental health issues. They did not state the conclusion that the crash was a malicious act on the part of the co-pilot.
It was only the final report that concluded the cause of the Germanwings 9525 crash was a deliberate and planned suicide by the copilot.Note
, I am using this example solely to show the normalcy of a slow, careful release of information by accident investigators even when the cause seems so clear that criminal investigators are already publicly preparing their case, not to favor murder-suicide as the explanation for the China Eastern 5735 crash over other possible explanations.
There may be details in the preliminary report, however, that make it pretty clear what the cause was. Or it may leave open too many questions like the AF447 interim reports.