I think it's a pretty common view that if you only fly domestic US, DL is pretty far ahead of UA. But who solely flies domestically?

Back to the OP - I think UA will copy DL, based on history and current revenue/loads. If we head into even more of an economic downturn, that could prove a mistake - but I'm purely guessing. It will be very hard to retain 1K for certain business travelers who are still not yet back into the customer/client project travel - and may never will be (in my case).