Unless there's a switcharoo, Lahabrea can't die in Pandaemonium because he alongside Emet-Selch and Elidibus escaped the Sundering.

Him being irredeemably arrogant or evil is still a possibility because he is that way by the time 2.0 comes around. 12,000 years later, he even had a moment where he had to be reminded by Elidibus that the work the Ascians were doing was by Zodiark's will and not for his own. After his death, his own fellow Unsundered called him an idiot, so I don't think he's meant to be a well-liked figure who will be fully empathetic, even among his own people.