Where Cassus Fett went, only he knew. Despite the Republic's best efforts to go after their former foe, the victor of many battles, including Jaga's Cluster, Cassus would remain elusive. His plans, Byzantine and complex, and understood only to him, would prove fateful. Eventually the Mandalorians would rise again, but not under Cassus. When the Mandalorians eventually united again under a single front, Cassus was nowhere to be found. It's surmised that despite his shadowy legacy, Cassus' influence and reach inspired other Mandalorians to continue the Crusade of Re-Unification, as it was later named by historians. Many Mandalorians, including a still unidentified Mandalore, and Feruun Lern, made attempts at re-uniting the Mandalorians. It was not until after the Jedi Civil War that the Neo-Crusaders would rise again under a single figurehead.
With the nuclear bombardment of Telos, the "Sitting War" had finally turned into an all-out war between the Republic and its former saviors, Revan and Malak. Beginning with the attack on Foerost, and other smaller campaigns, the war for the most part was oddly quiet as the Republic waited for the inevitable Sith attack. After Telos, however, the conflict became a full-fledged war on all fronts. Billions of sentients across the galaxy, from citizens to soldiers to crime lords to mercenaries, became involved in what was later called the Jedi Civil War.
The Asilyr tribe of Socorro retained a strong, unified front, even after Cassus left the picture. Eventually they settled their disputes, and proved to be one of the more peaceful tribes of Socorro. The Ibhaan'l as well maintained their peace treaty with the Asilyr, and lived on as merchant traders on the desert world for thousands of years.
Despite the lackluster ending to Douglas Fett's first bounty mission, the young Mandalorian would continue his career. Fett, like many other Mandalorians, had eventually found their calling during this time. While many tried to emulate the wars of yesteryear by becoming mere bandits and raiders on isolated worlds, others became mercenaries for the highest bidder. Fett's rocky start in the bounty hunting world was simply a small step into a larger galaxy.