As you have pointed out, a union could be used to promote worker ownership. Thank you.
The simple answer is yes. We seek alliances with all sorts of social forces to advance the campaign for social change grounded in a democratic transformation of the workplace. A social transition from an economy dominated by the capitalist economic system (the employer-employee division at work) to one in which worker cooperatives prevail (where employer and employee have merged into the same persons functioning democratically on all major enterprise decisions) is our goal. Once labor unions and worker coop organizations were allies in US history. I see no reason why that cannot happen again; it should.