So what are the chances of APA bringing the WOs into their union?

It actually works better for ALPA to maintain poor conditions at the WOs. Poor terms and conditions and a low Flow of 5+ means that more pilots will leave PSA for other ALPA carriers instead of waiting around to flow to a non ALPA carrier. Whenever a PSA pilot flows, ALPA loses money. Their is no incentive for ALPA to help any WO with a flow.