Perhaps because Dong Tianyu and his group were representing the Blue Star Plane Will to invade other planes for the first time, the information about the treasures obtained through the first use of the Sacrifice Array was relatively accurate.
In fact, Dong Tianyu already knew about the intelligence regarding plane invasions from the internet before being notified by the Plane Will when he was on Blue Star.
The intelligence disclosed online wasn't just some unverified gossip, but rather accurate information certified by the Imperial Court.
At that time, Dong Tianyu had not anticipated that the Imperial Court would gain so much knowledge about plane invasions by capturing those Otherworldly Invaders.