Yes, it's exactly what it means. He's the "manager" of his roles, and within the authority granted to this roles, he can make autocratic decisions that others can't veto (not even the "Lead Link"). And it's true for every employee in every role: they have full authority to exercise their role's authority.

Of course you need a way to modify the roles' definitions; there is a governance process for that, at each team level, and any team member can propose modifying the roles, not only the "Lead Link" (contrary to what this quote mistakenly suggests). I hope this clarifies a bit.