Originally Posted by
HighlordJohnstone
Nothing implies he was any kind of "Arbiter" before the actual Arbiter. Hell, it's implied that Zovaal wasn't even anything that special before his imprisonment. He was merely a part of the Pantheon of Death, much like how Sargeras was with the Titan Pantheon.
"whatever’s in her chest doesn’t match her at all but does the Jailers." That doesn't really mean anything outside of the fact that whatever the Arbiter has, is either drained by the fact that she's in a coma, or that she most likely stole it from the Jailer, which is why the Jailer's limited in power right now, and needs the covenant keys to get to her. It's also possibly why him slaying the Arbiter would be extremely catastrophic, outside of the whole "Oh yeah, killing the Arbiter would most likely mean the Purpose and the Cosmic Chart gets smacked across its head".
You're right on everything else though. Blizzard's straight up stated that the Maw wasn't the Maw before, and that's probably why Korthia exists tbh. Maybe Korthia was what the Maw once was, since it got lost in the In-Between, and is apparently right by the current Maw, and is also a broken fragment of the area.