A "brighter line" drawn to include, or to exclude Calvinism?
Exclude, of course. Our disagreement with Calvinism is that we believe that Christ redeemed all sin and wished the salvation of all; yet not all respond to the call. Thus both “for all” and “for many” is a true statement, deppending on the intended and unsaid here, context. The rise of calvinist thinking, I suspect, drove the desire to avoid the false conclusion that the Church teches limited atonement, drawn from the Epiclesis.