Can the fallen angels lose their souls and disintegrate into space dust to be recycled if they don’t return to the light? What are the odds this will happen?

This is an apt description of the potential for their demise, and you have been told this before, in the descriptions of soul recycling, which is the ultimate form of healing for those beings reaching such an extreme point of deprivation. Their suffering is too intense to bear, and they are so far away from working their way back up, that it is in their best interests to terminate the suffering, even at the loss of their existence. This need not happen and will not happen with the current plan envisioned. What we see is the possibility of healing for all, with humans leading the way. This will turn things around and will benefit all beings involved but must be chosen by the divine human for this to happen.