The gnostics — Book of Thomas, Book of Mary, Book of Judas, etc., are also centuries old too. Same for the Quran. — That doesn’t mean I believe any of them.
There are some very logical reasons the gnostics aren’t part of our Bible. This new centuries old find would fall into the same category.
You are right. The naysayers and heretics will not inherit the Kingdom of God, or be part of Jesus ‘Bride Supper of the Lamb’. Choices have consequences.