All you are offering is your speculation about the Christian canon that you believe was set in the first century.
Nobody who understands the history of the Christian Canon believes anything was set in the first century. Only someone completely ignorant about the development of the Bible would think it was "set in the first century" since nothing was set in the first century.
And was answered in your other thread, there was no final authority or governing body or agency of any sort that "decided" or finalized the Canon. The Canon did not develop by someone or some group on the top deciding things by fiat--that never happened. There were lots of people, people whose voices were respected, offering their own thoughts as part of an ongoing discussion and debate about which books should be read as part of the Church's cycle of liturgical readings, and there were small regional councils at various times which discussed this exact issue relevant for the jurisdictions themselves (such as Rome, Carthage, and Laodicea).
But the simple fact of the matter is that the New Testament Canon was arrived at by a general consensus, by what was happening in the churches themselves around the Christian world. Which is why ancient writers make a distinction between Homologoumena (those writings which had attained a universal acceptance early on, such as the four Gospels and the thirteen Pauline letters) and Antilegomena (those writings which there was not a consensus on, but which were disputed, such as 2 Peter, Jude, James, the Revelation, 1 Clement, Barnabas, and the Didache).
And those two categories of writings existed long before Constantine, and continued to exist long after Constantine.
Early western fathers were highly favorable toward the Apocalypse of St. John (aka the Revelation), but this was not universally true as the book was heavily contested in the eastern churches for most of the 1st millennium, this can actually be seen reflected in liturgical differences between East and West. The western cycle of readings includes readings from the Revelation, the eastern cycle of readings does not--because both cycles (the three year western lectionary and the one year eastern lectionary) developed well before a more general acceptance of the Revelation happened.
And on the other hand regional differences continued well into the middle ages, as well as other quirks. At some point the spurious letter of Paul to the Laodiceans found its way into copies of the Vulgate, which is why John Wycliffe includes it in his 14th century English translation of the Vulgate (Wycliffe Bible
here), and 13th century versions of the Armenian Bible contained the spurious letter of III Corinthians. These works weren't even Antilegomena, but rather spurious texts pretty highly regarded in antiquity as spurious, but nevertheless found their way into usage or at least in copies of Scripture, at least for a time.
The fact is we can't point to any single time, place, or person(s) as to the when, where, or who of when the Christian Canon was established. Because there was no definitive when, where, or who; it was an organic process that arose not from people on the top dictating things for everyone for all times, but happened at the ground level. It was what was going on in the churches themselves, when people came together for worship. Which is why we speak of the development of the Canon as coming about by consensus, because there was a developing, growing general agreement about the books which make up the Christian Bible over the course of literally hundreds of years.
As such asking "Who did it?" isn't answerable, at least not in the way you want it to be. The only historically and factually accurate response to "Who did it?" is to answer
everyone. The Canon wasn't an autocratic process, but a thoroughly democratic one; it was historic, general acceptance of Christian people, both laity and clergy, over the course of many centuries.
-CryptoLutheran