The no-god would replace the outside, connecting the souls of men with the world. Thus all men can feel where Mog is (until he enters the ground itself).
The text is replete with examples of how the ground witnesses and remembers - Kellhus even talks to it.
Earwa remains the point of maximal objectivity, but now the Consult are furnished with power to create their own sub-realities in the new outside rather than burning in damnation.
The 144k are required to power the new outside - extermination of humanity was never really part of the plan, the Scylvendi are proof of that.
Further, the design of Scylvendi culture shows what type of world the consult seeks to produce - no progress and a steady supply of brutalized souls for the neo-gods.