What I liked about the Ancients in Shadowbringers was that they were basically just a better form of humanity. More long-lived, more powerful and more compassionate for their fellow man. There really was no argument as to whether or not humanity as it stood was better than them, because they weren't. I feel like it severely detracts from the effectiveness of Emet-selch as a villain if he were just wearing heavy rose-tinted glasses and everything we saw about them was an overly idealized lie. He'd been living among the Sundered for centuries and bore witness to every one of their flaws. I really liked it when for once there is a scenario in which life as we, the protagonist knows it, loses out. A moment where we sit back and consider that maybe this man has a point. Of course Emet-selch is still a villain at that point and I'm certainly not saying he was right, but antagonists having real valid points against the protagonists is what adds that much-needed depth to conflict. I'm trying not to let Endwalker spitting in the face of that get to me.
That being the case, desiring a fully rejoined Azem seems to be counterintuitive to this idea. Ardbert rejoined the WoL because a soul of that density was needed for the WoL to fend off the light of the Flood. I don't think, were he given the chance to be himself again, that he would choose to stay with us. The same goes for any Azem counterparts in other shards. Why should they surrender their lives so that they can join some greater whole that may not even resemble themselves anymore? They should be free to live their own existences. The circumstances are actually rather similar in nature to the Nobodies in Kingdom Hearts, which I can't help but mention.
As an aside, I think it would be cool to have a future antagonist be the Voidsent of Azem, their 13th reflection. No particular reason for saying that aside from it being a personal wish of mine with a lot of potential, but I'm very curious about Azem's other fragments.