The First Order is driven back to the unknown regions, unable to compete with sheer numbers and resources the Republic could employ. Whatever is left of their foothold in the outer rim -- colonies, mining operations -- are retaken by the Republic. Only it doesn't stop -- What other species has so proliferated the galaxy? Brought so much misery? The galaxy has been saturated by humancentric government for too long. The Republic takes a hard anti-human stance. Planets start ousting them, especially Imperial descendants, leaving the refugees in the lurch with nowhere to go and no one to turn to.

+ Snoke's dead/gone
+ Human refugees are steadily driven further out, flush against the unknown regions
+ the FO is still relentlessly patrolling the edge of their territory, the ships just close enough to be visible. They may not be able to expand, but it would be suicidal to try to take their established territory.
+ they don't contact the settlements, even though the Resistance is certain they're monitored
+ this puts the them in a predicament. Throw themselves on the mercy of the Order? Eke out the bare bones of survival, crushed between two powerhouses, hoping neither decide to snuff them out? Keep lobbying with their dwindling pool of allies?
+ a cadre of ships -- Republic or independent -- approach the settlements and the FO responds aggressively, dropping star destroyers overhead (+ the Finalizer herself)
+ How quickly they go from chilling portents of terror to being ecstatically welcomed as saviors