Why not report the cause of the air crash in Wuzhou, Guangxi?

Before the final air crash investigation report is published, it must be guaranteed that the conclusions in the report are completely in line with the facts and proved to be the real cause of the plane crash. China Eastern Airlines 32 1 Wuzhou air crash, the whole plane disintegrated, and all the people on board were killed. Investigators have few clues to find the cause of the accident, and it is difficult to get the cause of the accident in a short time only by the data of the black box.