Especially at this critical moment, if they can immediately seize the authority of the Qingling Primordial Lord to help Ju Mang Ancestor Witch ascend to Taoist Monarch, this is the most important thing for the Witch God Sect, and everything else is irrelevant.
One reason Zhu Jiuyin doesn't make a move is actually because of apprehension; he doesn't dare to take action for now.
Although Zhu Jiuyin Ancestor Witch displays the Sixth Heaven Realm of True Immortal, his combat power is not merely measurable by the Sixth Heaven. It's not an exaggeration to say he's at the Taoist Monarch level, which many Taoist Monarchs acknowledge.
If other True Immortals provoke Zhu Jiuyin, and he fights back, even if other Taoist Monarchs know about this, they have no reason to reproach him.
However, if he takes the initiative to act, it would cause negative effects, at least allowing some Taoist Monarchs to see it as bullying the weak by the strong.