Again, I think everyone's in agreement that Bad Things are allowed go happen. No debate there. The question was: where does the Hardholder go from here? So let's talk about the question.
As long as there are still people taking orders from him, he's still the Hardholder as far as I'm concerned. Maybe he wants to rebuild or settle elsewhere? That's all up to him, of course. Ultimately, the player has the choice to stick with the Hardholder or retire him. If there's no townspeople left, I think it's legit to switch playbooks. Make sure it makes sense in the fiction, but I see two obvious choices: If there's still a gang but no townspeople, the Chopper might make sense. If there's townsfolk but no gang, maybe he's a Hocus now.
In the end, you gotta just ask the player if the character's saga is over or if this is just a new chapter.