The aim of spiritual seeking is often enlightenment. With Non-Duality the aim, once one understands the teaching, is to realise the non-dual nature, to achieve Liberation, Enlightenment or Self Realisation. There are lots of questions about this, sometimes about the fear of totally letting go of everything. Let's consider that.
Certainly, for Self-Realisation there is a need to let go of everything. The other terms mean the same really, Liberation, Enlightenment, Moksha, Nirvana, etc. They all point to that recognition of Reality as it is. That Reality is without limits or division. So the person we think we are is not who we really are. Spiritually minded people, of course, would recognise that they're not the human body. Some may believe that they are a soul.
The soul is and isn't accepted in Non-Duality. It is accepted as being part of the play of Maya, the illusion that is the appearance of the world. There is the material dense world that humans live in, and there is the finer, hidden world of souls and the spiritual realm. This includes the development of the soul, incarnating in human form, getting caught in the wheel of Samsara, the endless round of rebirth. The soul lives life after life after life, learning, making mistakes, getting tangled up in karma. But in Non-Duality this is seen as the play of the Infinite One Being seeming to become many, but not really.
We could consider souls as sparks of divine spirit. But that's not strictly true. They're not really sparks of the divine spirit released into the world. The world is the Divine Spirit, only appearing to be less like or more like the divine. Just as the human body isn't really limited, neither is the soul. There really is no divide in the Infinite One. What seems to divide the Infinite One is also the Infinite One - the space and the substance are the Infinite One.
So we can say the soul seems to be limited but really isn't. It takes on human form and experiences human life. That's what's happening here. The human world is heavy and dense. Dark clouds loom over it sometimes. Humanity is limited by the hardened physical limitations of matter and the hardened mental limitations of the human mind. The human mind develops a pointed sense of itself as a separate individual in a competitive world. This is the opposite of Reality, which is selfless and limitless, whole and complete. But the human experience allows a lot of possibilities. Personalities develop. There is a great variety in the One. All humans are different and express their particular developmental experiences as well as the influence of the soul.
The release of the soul from the endless round of rebirth comes when the soul's attachment to matter and form is dissolved. This comes about when the sense of being a separate self is released. It is the Self-Realisation that there is no self. It is Nirvana, the extinguishing of the sense of being a separate self. It is Liberation, freedom from the bondage of illusory limitation. When this Enlightenment occurs, when the sense of being a separate self is no more, there is no subjugation to karma. It is clear that not only is the body unlimited, the mind and the soul are unlimited. This means that there is no body, no mind, no soul. There is only What Is. This What Is is here right now. It is only the sense and belief of limitation that makes it seem otherwise. But that is the development of humanity in this time.
So when Self-Realisation occurs, it doesn't mean that the world ceases to exist, being sucked back into the Singularity. The Singularity is always timelessly here. Nothing changes, only the sense of being a separate self is nowhere to be found. The human in which this realisation occurs does not identify as a human, a mind, a soul, or anything. It just is. Yet the human life continues. The Awakened Human (for want of a better expression) still has its personality but without the person. It has its flow and role in the human world, as momentum has always been active in it anyway. The human life changes in a way that it is no longer guided by the selfish aims of a separate self. There is no ego in the Awakened Human, so the human life flows naturally with the way of What Is.
Similarly with the soul. It doesn't mean that the soul is dissolved upon Self-Realisation. The soul flows with the spiritual nature of the universe in further play and adventure, in the Divine Play of Multiplicity.