The existence of the "Void Quests" at the Crystarium seems to make it unlikely, or at least difficult for plot integration, to have the MSQ also deal with the void. As much as they haven't really made any progress, it feels like setting the stage for a later continuation – assuming it didn't just get dropped due to COVID – but even then it could get picked up again later.

And it has such a long shopping list of prerequisites: all the role quests, and the capstone, and all the Warring Triad and the associated extreme trials (including the need to beat Bismarck and Ravana to continue those quests, as simple as that is to do unsynched). It was even speculated by fans that they might plan to integrate the Eden quests in future.