Minfillia never reincarnated though. She possessed others, much like the Ascians do, until she eventually allowed herself to be subsumed into Ryne. Gaia however was dispersed into the lifestream to reincarnate naturally. Besides if Gaia did reincarnate other times it seems strange for Mitron to not mention so, given that he can communicate with her on some minor level, even while stuck as Eden.