I don't buy that one...God provided the Apostles with the ability to provide miracles to the unbelievers in the absence of scripture until the scripture could be recorded...
And that process was completed and ended with the book of Revelation penned by John the Apostle...
With the death of the Apostles and advent of God's words on paper and the indwelling of the Holy Spirit in the believer, not only did the office of Apostle end, but the Apostolic miracles ended as well...
And I am confident that there were enough copies of those scriptures during that time to satisfy God...
But naw, God didn't grow his church without the written word...
Prior to the written word, God used miracles to show his power...He shortly changed to the power of his written word to gather the lost...