Nobody knows that - it's not like anybody knows him personally.
He's maybe a few chapters ahead if he is already but not much. He gave his schedule once and it showed he had only four hours of rest per day every week. If he was further ahead he could take longer breaks.
Plus each chapter has to be approved by the editor. If it's not approved, it has to be drawn again so that takes time as well. And him giving a chapter each week if he's further ahead, is not something that he can decide. It's the publisher's decision. If they decide to not post chapters for a week, then the mangaka have no say in that.
So he's probably not far ahead, but we don't know about it because he never said anything about it