I read that AA categorizes all delays, cancels, and misconections into two categories: "schedule irregularity" and "force majeure".

The difference is that in a force majeure event, AA is obligated to ONLY refunding your ticket. They may book you on another flight but they are not required. For schedule irreg., AA is responsible for rebooking your flight and may provide hotel accomod provided certain requirements are met - rule 240C and E) and provide a refund should one not accept their alternative. Note all of these are in theory, actual experience may vary.

So, does this "job action" constitute a schedule irrgularity or a force majeure? In any case, at least currently AA is trying to book passengers on other flights or on other airline's flights (from today's AP report).