I think it's less that the stuff would be considered heterodox, as just not as good/relevant. Like certain texts were used in the Roman world for school, just kind of universally taught to the literate class. The Aeneid was one of these but before it was written the Annales by Ennius was the classic poem everyone had to learn. Then the Annales became less popular, stopped being taught, and now we only have some fragments of it.