If this threat is really being planned and not just a conspiracy, this simulation would be helpful to gauge industry and government preparedness and find chinks in their defences, without letting everyone in on the plan. The information can be used to adjust plans for maximum probability of success.

It would be good to look at who/which industries are participating to get an idea of who could be on their target list. They'd want to invite their victims to scope them out.

Best time to strike would be before the industry and government has had time to fix the flaws found in their preparedness (within a few months, since big companies and government move slowly).