Lore question: The Xindi

The problem with a prequel, Enterprise, being the last series in the Star Trek franchise is that they introduced a cornucopia of new species that had no mention from TOS through Voyager. Where do the Xindi fit in with STO? I've seen some of their ships, but where should the region formerly known as The Expanse appear on the map? What became of them after Archer prevented them from destroying Earth? My highest level achieved so far is 59, so is there a Xindi storyline still in my STO future?