I mean again, the reason for that event was due to Azerite a byproduct of that thing THAT EVERY FORCE IN THE UNIVERSE WANTS. (AZEROTH) Because, again the Vials stolen from the Well of Eternity which as it has been retconned in the Chronicles was the Lifeblood of Azeroth which as we've established with BFA is extremely powerful and can do miracle level shit.
Obviously if there was other ways to restore Naaru from Void Naaru then Light would Dominate the Cycle for all eternity.
The same goes for why Alleria did what she did, it's not like the Void needs to take control to get what they want out of that event. Which I mean they just randomly popped up so again.. Also her dialogue literally makes it pretty obvious she didn't know what would happen when she interacted with the well.
Once she interacted with the Sunwell the portal opened and the Void invasion occured which again is due to the whole Azerite thing again. (Cause there's no other explaination and the void knows everything anyways.)
Again if we now understand why the M'uru purification sequence and the Void Invasion at the Sunwell, it is just again a smaller scale example of the cosmic war for Azeroth and her powers.
Fundamentally, I just think there's a lot of nuance to the whole Void Mind Control and Void Suggestion that lead to events. Either way, Alleria is a good walking pawn and we've already seen that established with what transpired at the Sunwell.