I read it a different way, as in... we think you might also be a member of another FF programme, but you can still fly QF and get the flights credited to your other programme (if you want to favour that programme over QF FF). I thought they were trying to get you to fly more with QF.
+1. Variables like this are meant to increase revenue by selling more products and services. I read it as fly with us and credit to your other program if you wish. This may be the result of a data swap between QF and another OW carrier, or you may have credited points on a QF flight to another program already?