It should apply to research rates as well -- though it's not 200% your rate, it's 200% the rate they would normally be entitled to due to their number of labs, scientists, research rate tech, etc.
Though all of that is largely irrelevent as there is a bug associated with setting the difficulty above 100%. Doing so will eventually crash your game as the NPR spends more minerals than it thinks it does, and then runs out.
Fatal error. Crash. End of Campaign.