The fact that the Brokers say she sees every choice, every truth indicates that the Orb is the remains of a Void God.
Mueh’zala is said to be the son of Time… Furthermore Naaru can cause localized Time Stops(which have been used in the Mag’har Allied Race Scenario on Mag’har)… What if this “Time” entity is the Void God that the Arbiter(and formerly the Jailer) contains within herself?
If the Arbiter is Elune like this fan suggests then the Void God is likely the creator of the Naaru Prime and is thus the first Naaru…
If the first Naaru AKA the God of Time(which makes the Naaru Time Elementals drawing on purest Light not Light Elementals) ends up being the Final Boss of Shadowlands then things might get very interesting for the next Expansion since the Naaru will desperately try to grasp any clear enlightened path available to avoid falling to Shadow.