Originally Posted by JJeffrey

If you are just looking at aa.com then the "SWU Availability" link will not show up for a multi city search but will for a roundtrip or one-way search. This has nothing to do with the actual SWU availability but is just an aa.com bug.

But if your flight shows as available when searching roundtrip then it should be bookable, I would confirm though that you are interpreting the results correctly.

If you can provide the flight/date then I can double check the availability on ExpertFlyer which is much more reliable than aa.com.