I posted a more general version of this question in TravelBuzz, and didn't get a whole lot of response, and it occurred to me that it might help to reframe it in a more specific (and UA-related) way and see if anyone here has any insight.

I spend roughly every other weekend in LA, flying NYC to LAX/BUR and back, always on UA. I'm trying to get a bit smarter about when I buy tickets.

I've spent a while now learning (mostly from threads here) about how fares and availability interact to generate ticket prices, and now I feel fairly fluent. I can check the information on AVS/EF (I haven't figured out which one I like more) and accurately predict what the price will be on ITA. Learning about fares/availability has made it so that I can tell if flights are expensive due to a lack of a cheap published fare (e.g., EWR-LAX until the VX route starts in April) or due to a lack of fare class availability (e.g., LGA/JFK-LAX for weekends in March). What I haven't quite been able to do is figure out how to use my new-found knowledge to get better at predicting fare increases/decreases.

Do people have any tips about how United behaves in terms of opening up fare classes? Perhaps the answer is that these things are hard to predict and depend on the unpredictable behavior of competitor airlines. It seems like maybe this is all more like an art than a science, and I need to just get some experience seeing how things work out. I just wanted to ping the masses, though, and see if anyone has any tips.