I figured that is why they did it the way they did it. He disappeared so if his film career flops or he gets some free time or whatever he can easily pop back in.Poor Ronnie. Makes some sense from a storytelling point of view as they can use Professor Stein in a more professorial way for these first few episodes without making things easy by having Firestorm ready to save the day at any moment. Wondering, though,when the new guy comes in and where he gets Ronnie's half of the Firestorm matrix. I keep thinking that they are saving Robbie Amell to maybe come back at somepoint, but not sure as what.
He's probably on Earth 2.