Yes, accuracy is very important. But at this point, first ever preseason game, I find it hard to quantify. Is he fully in sync with his WR's yet? Maybe he threw the ball right where he wanted to but the receiver wasn't exactly where he expected? Ran a route at a slightly different depth?
At this point I'm much more concerned with how he looks out there. His command of the offense. How he calls the plays, gets guys lined up. HIs poise, pocket presence, and decisiveness. Stuff like that.