Only matters when you sold it. if it goes to $600 you have a big loss on paper but it goes down to 499 by Jan23 you keep all your money that you made from the credit
Actually if stock is at $500 after a period of increase ( say it is now much above the MDA 50) you add a certain margin of safety that Ziv calls "insurance" (say 10%) and sell a call at 550 to be extra safe. So no, you donot sell at 500. That's too "unsafe".