CC was not saying that p46 reads κοινωνία here. It is κονομία. If I understand him correctly his question was about whether the *exemplar* of p46 might have read κοινονια, a form of κοινωνία, and it got written as κονομία here. I do not think he was dogmatically saying this was the case but just raising the possibility. If this were the case it would support the TR reading at Eph 3:9.
Again, my point is to say that p46 is not (for whatever reason) a clear witness for οικονομια. Therefore, it takes the number of extant pre-800 witnesses down from six to five and means there are no clear papyri witnesses for Eph 3:9, and it makes the earliest clear witness to the οικονομια reading a fourth century uncial. I think these are facts upon which all can agree.