First, it's silly to expect a company to be making public disclosures before it has its ducks in a row and can explain precisely what happened with a reasonable degree of accuracy.
Second, the idea that the act of being hacked is prima facie evidence of prior securities fraud is absurd. Assuming that a company took good-faith efforts to secure its systems, it wasn't lying (see mens rea above) when it said things like "we use strong passwords." I'm sure there's a point of gross incompetence or negligence that could get the company in hot water, but barring that, sometimes you just lose. Sometimes the robber picks your house and sometimes the hacker picks your company.