While the Nag Hammadi texts are a major resource of Christian thinking after the first century, they are not as old as the oldest gospels, which is why they were not included, not "banned" (clickbait title).
Thomas is a collection of sayings, and it has some problematic texts, including real misogyny, that make it unacceptable. But you do know that there are sayings of Jesus such as "Jesus answered, “Is it not written in your law, ‘I said, you are gods’? (John 10:15, quoting Ps. 82.6); and "Once Jesus was asked by the Pharisees when the kingdom of God was coming, and he answered, “The kingdom of God is not coming with things that can be observed, nor will they say, ‘Look, here it is!’ or ‘There it is!’ for, in fact, the kingdom of God is within you.” (Luke 17:20-1)