There is a Theory, personally for years "In Held Twas In I"*: When the Multiverse once again collapses to a singularity, as is its cyclic wont, many trillion years from now; those of us who have 'kept the faith' and survive down through all the long, dark, lonely aeons after the last star goes neutron and all remaining matter inexorably . . . slowly . . . moves to the center, may find fewer still that then remember the Oath: "No living being should EVER be sacrificed."^ These last then will once again attempt what we KNOW to be possible, demonstrated by that miraculously lucky handful of Souls, who made it through the "last black hole" become solely energy: radiation remaining coherent through the event horizon and beyond as another "Big Bang" again begins the familiar expansion . . . diastole . . . sytsole, ad infinitum. And if we have managed to hold on to enough, the nature of the next "Wheel of Dharma" may NOT be: "Life Feeds On LIfe" ever again. We pray that some new paradigm: co-operative and NOT competitive, will prevail . . . and we will scrutinize with great care the new mechanisms of evolution as systems and data, and we will attempt to recognize any flaws that might cause suffering, and vow to carry our aspirations to correct such flaws through ongoing analysis and improvement as long as we can bear.
Thus, the repeated tempering of Will and drive to survive, and the testing, again and again, of the coherence of our creed through innumerable events of apparent total dissolution, which we know once again - through which we have managed to proceed and beyond which we have found ourselves AND our centers before - this process of return to the raging entropy of THE Creative (Hexagram 1: CH'IEN Force/Dragon) may be The Way The Tao forges itself to always progress, and improve. So perhaps without this reunification - "trial by Dragonfire" - the ultimate test of one's faith in one's self: to dissipate entirely, and yet somehow to be successfully reformed, proof of the preservation of self and the perseverance of purpose might not occur with as much persuasion and punctilio.
Perhaps THIS may be one explanation pertinent to your request: PRACTICE MAKES PERFECT ! Here is a hidden insight into a possible reason for multiple Grand Cycles if you, like me, accept the premises of the supposition of ultimate intent. If so then here is a precious epiphany and solution to any self-doubt about surrender of self-control, designed to recur as the compulsion to prove the truth of one's Faith through the experience of inevitable indestructability, absent of ANY control of self or assertion of control, thus confirming the ABSOLUTE and OMNIPOTENT essential control inherent In The Tao as illustrated through the conundrum of Return To The Tao - theDalphe.
*Procol Harum '68 ("to which I lend creedence")
^Jainism: "ahimsa"