Incidentally, these practices remind us forcibly of the fluidity of all manuscript traditions in antiquity. What we would call an edition simply did not exist in antiquity; ἔκδοσις (usually translated with "publish") merely indicated the stage at which the author let a version out of his own hands. Copying was basically ad hoc, determined by innumerable factors and completely outside any formal control. It is impossible to speak of fixed traditions. . . . When we think about books in Greco-Roman antiquity, we should accept that single, final autographs probably never existed. In reality many participated and contributed to textual traditions endlessly in flux. (347; original emphases)
The phrase, "endlessly in flux," seems a bit exaggerated to me. But the point that writing a text did not fix the tradition is well taken. Too often, NT scholars talk about writing as the point at which a variable oral tradition becomes fixed; oral traditional scholars (both inside and outside biblical scholarship) have known for quite some time that written texts are only as stable as the cultural practices that facilitate their use.