If both cards were issued by the same bank it might be feasible to exclude CSR cardholders who are also co-branded cardholders, but doing that across two banks is probably too complex and would involve sharing data from one bank with another.
Possibly. I just find it interesting that they also just took some steps to force use of AS Visa cards for benefits like free bags and priority boarding (and a companion pass tickets), and previous Offers campaigns have targeted my AS Visa (but also my CSR).
AS’ computers know I have both cards since they are part of my AS profile, but they may not be able to leverage that information in marketing campaigns like this.
In any case I am glad that of all my cards they targeted the CSR.