Tao Qian purposefully revealed the name of Duobao True Monarch, clearly aiming to borrow some prestige, first to intimidate the Three Demon Immortals of enigmatic origin before making plans.
By pinning the label of Evil Demons on them, and then suddenly revealing the truth, he hoped to bluff them into exposing their own roots.
Such actions were naturally because of the future Record glimpsed by Tao Qian.
These Three Demon Immortals were indeed called the "Three Immortals of the Miraculous Tree," and they indeed had not secretly harmed the Spirit Treasure Disciples who had come for Foundation Establishment.
However, why did they drain all the Essence Blood and Primordial Spirit from the dead disciples, leaving only an empty husk?
And, why did his own master, when sending people up, not reveal the existence of these Three Immortals of the Miraculous Tree?
If one were to say that Duobao Daoist did not know, Tao Qian would be the first to disbelieve it.