They made their own choice. They chose family.

"So it was just to spite Zachariah, then? You're unbelievable. I thought you above games like that, Gabriel." Castiel shakes his head and turns around, walks to the bedroom that holds his bags, but lingers in the doorway, shoulders tense. This isn't the first time he's been wrong about Gabriel, but it doesn't sting any less for it. "Consider yourself free of your position. We both know there is no need for an honor guard, and we both know you have no wish to be in my company." Castiel's tone is still clipped, but the hot anger has drained from it. What he's talking about now is not a raw, fresh wound, but an old pain that he's learned to live with. A pain he's trying to hide from Gabriel by attempting a retreat to a bedroom he can actually shut and lock behind himself.