I’d say it’s a big developement as we’re waging a global war on terror. Declaring an arm of the Iranian military a terrorist organization could be considered tantamount to a declaration of war against Iran.
That’s my take on it. It atleast provides justification.
It would put the Iranians on the same footing as the Taliban, and tend to make Iran subject to the Authorization For Use Of Military Force in Response to the 9/11 Attacks :
That the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons.The timing of it, along with other stuff happening, indicates that D-Day is approaching quickly