We imagine Matthew the Apostle sitting near Jesus writing His words in short hand, or frantically trying to keep up, lest he miss a phrase. From my browsing, Matthew was first written 80-100 A.D. and how much Apostolic Tradition became part of Matthew (or any of the Gospels) cannot be certain. I don’t know when the first extant copy was quoted by the Fathers, so there is a difference between the first written copy, and an extant manuscript.
There are legions of cults claiming that Matthew 28:19 was added by Constantine. Making painstakingly accurate extant copies was the job of humble monks, not an emporer.
This theory also falls flat when you look at the Didache, which was written around the same time. The Didache was AUTHORITIVE, and almost made it into the Bible.
DIDACHE, CHAPTER 7 - CONCERNING BAPTISM
- And concerning baptism, baptize this way: After reviewing all of this teaching, baptize in the Name of the Father, Son, and Holy Spirit, in living (running) water.
- But if living water is not available, then baptize into other water; and cold is prefered, but if not available in warm.
- But if neither is available, pour water three times upon the head in the Name of the Father, Son and Holy Spirit.
MATTHEW 28:19
"Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit
Even if the cults are correct, and Matthew 28:19 was added later, the teaching and practice of the earliest Christians certainly wasn’t added, and I am sure there is more evidence countering anti-Catholic lies than what I have offered.
Gospel of St. Matthew (Catholic Encyclopedia)
Didache