It would be a metaphor as to how humanity is to repeat the same mistakes over and over. Magus would inevitably become what he used to be. A second war against Guardia would show that perfectly. Magus, being oblivious and all, would easily succumb to Dalton's knowledge. He'd see him as his best chance at regaining his memories.
As interesting as this metaphor would be, it's not grounded in anything. How is Magus oblivious? He's naive when it comes to Lavos, but almost everyone was. And when it comes to being outwitted by Dalton, I seriously doubt it; the man may have no memories, but that doesn't mean he's devoid of reason.
Look at the reasoning behind Magus's attack on Guardia in 600ad, it was basically used to summon Lavos. And even though it was Ozzie who first realized Magus's potential (similar to how Dalton would in the Dalton/Magus scenario), Ozzie still ended up being a right-hand man. Ozzie rallied the support of the mystics, fueled their fury towards humans, and led the raids on Guardia, while Magus remained in the background as the supposed leader of the Mystics. Magus is clearly cunning enough and manipulative enough to use Ozzie as a pawn in his own schemes--even as a younger Magus, he was still an authority to Ozzie. These memories may have faded away, but these instincts are still there. Magus is one of the greatest magic users of all time, would he really be used as a pawn by Dalton?