Is The Secret That Viserys Targaryen Shares With Rhaenyra Considered Canon?

[Herbert Playz]

Polygon had an interview with one of the showrunners Ryan J. Condal. And according to him, George RR Martin is the one that revealed to them that Aegon wasn't just a conqueror and actually had a dream about the end of the world and that's what motivated him to conquer and unite Westeros. In preparation for that cataclysmic event.

That sounds pretty canon to me, I'm guessing something about this will be revealed in the next book The Winds of Winter.