Are those (>16 segment) tickets currently issued electronically? My understanding was that Sabre couldn't handle more than 16 segments electronically (which kills it for AA and, by extension, OW). If *A can currently issue >16 segment tickets electronically, then there would presumably be no reason for them to change. Whether or not they can currently issue such tickets is presumably a "known" fact?
Not all (in fact far from it) airlines use Sabre
Admittedly my last *A RTW was paper ticket, but I know I had some non-eticketable destinations included so I am unsure whether they can handle 24 segments electronically.