I thought the concept behind Polaris was to compete with AF, BA, LH, TK, KLM and the other international non-US carriers with nice lounges and often pre-flight dining (BA and AF in particular), not against other American carriers, either transcon or international. Which at the time they were clearly falling behind in hard and soft product. So it seems unlikely that they would expand PLs beyond international business class. When they reopen that is, which, in order to save money, probably won't be until they think they have to.