Multiple posters have complained (or expressed bewilderment) that Boeing did not quickly issue a statement regarding the cause of the fire.
One factor may be that Boeing is a publicly traded company. My understanding of United States securities laws is rusty, but my recollection is that publicly traded companies can be sued for making statements that later are alleged to have been false or misleading and thereby impacted the stock market. A small army of American lawyers grew very wealthy by filing many such claims, whether meritorious or not (the cost of defending the claim can be so great that a company pays just to stop the bleeding).
The law governing such claims has changed considerably in recent years, and is now less favorable to claimaints (and their lawyers), yet it surely remains a consideration.
No doubt Boeing's lawyers are carefully reviewing any prospective public statement with that in mind (along with other potential legal issues).