Yeah, I suppose we are assuming it unless something establishes otherwise. Personally, I don't mind the idea that the New Mandalorians ultimately fail, that they tried to save their culture from continual self-destruction and only ended up doing more damage to themselves than they ever could have originally (working with Darth Maul can't exactly help when it comes to attaining peace). Not destroyed by the Jedi or the Sith, but by themselves. If there's a "tragic race" in Star Wars, it's the Mandalorians. Depending on your perspective, I suppose Spar, Fenn Shysa and Boba Fett reforming the Mandalorians in something more akin to their warlike roots could either be a triumph (take that TCW!) or a tragedy.