The Supramental Manifestation is likely to follow a similar curve except that .... there will be no crystallization into fixed format Religion this time but a constant progress from light to greater Light
... a body becomes the field of the Yoga joining the two extreme poles of consciousness, the material and the spiritual, reconciling their opposition in a fulfilment of the Divine Intention
Nirvana in the sense of freedom from Ignorance that comes by realisation of the Divine within through the psychic door is indeed the first step of Integral Yoga.