The reformists are unfortunately a foundational split among the Islamist faction of the Revolution. They've existed since the death of Khomeini and end of the Iraq War. They've even forced former presidents to resign due to protests. Since they're basically the direct representatives of the corrupt Iranian bourgeoisie, they're very hars to dislodge without a socialist/worker oriented mass movement.

Though, currently a mass movement exists, actions like this are their attempts to diffuse it, and return Iran to the endless internal tug of war it was in before. Personally, it's hard for me to predict whether they'll become irrelevant after this war or not. Iranian reformists are very good at being political chameleons. They're politicians shift fluidly, and their rhetoric also changes to suit the moment.