Jan 6th didn't "cause" catastrophic risk. Events like jan 6th present huge potential risks.

If the insurrection had been successful the best case scenario would be economic collapse and possibly civil war in the country where these platforms are based out of. It is likely that many states would reject the sovereignty of the federal government if it didn't honor the outcome of the election, and from there things would quickly spiral out of control.

The potential outcome from the end of democracy in the us would entail catastrophic risk for the companies based here.