AS metal cannot be flown on OWE tickets. Any OWE including Africa must be a minimum of 4 continents (ie. all OWE include Europe, Asia and either North or South America). The rules are that the pricing is the higher of country of origin or country of sale, so BA is very happy to sell it to you in JNB but for the much higher South African OWE price (haven't looked but guessing double the ex-HRE purchase price). Don't have time to check your routing and with the AS flights gone it is likely to change drastically. AA does have DFW-ANC and ORD-ANC service but it is seasonal (June to mid-September).