There are still so many things that could still happen for Phantasy Star. Personally if they ever go back to Algol, I'd like to see a game centered around how Waiss unified Palma.

But in terms of OPs post, there is something that needs to be considered. Reiko Kodama may actually be right. The events that are playing out now in PSO2, what if it's all a prequel to the Algol series and the battle between the ARKS and Shiva is the battle that was spoken of in the intro to End of the Millenium?