I've read that theory before. I can't say that anything looks off in it, but then again, I'm no expert on PSII.
When I had finally finished PSII, the first thing that came to mind was that they probably had all died in the end. The whole setting, to me, strongly suggested it. If they had survived, then wouldn't they have been blamed for Mother Brain's destruction? Possibly even punished for the downfall of their technology? Maybe, in the end, they did survive the many many earthmen and returned to Dezo (Dezolis, Dezoris? ...confusing translations, sticking with Dezo for short) to give Lutz the Aero Prism before returning to Motavia and were, sad to say, executed. Lutz from there could've taken the Aero Prism to Motavia and kept it at Soldier's Temple, then returned to Dezo to lead the Espers.
Either way, I don't see anyone surviving in the end. Just my two cents on the matter.
