As to OP CSR comment, I agree it might be good advice. Today I asked a CSR rep if anything was likely to impact customers this weekend with a Single Operating Certificate, i.e. should I reschedule, not check bags, etc. I was told not to expect anything different this weekend, that the big change would likely be early March when everything went onto SHARES.
As to the actual IT systems, it sounds like contract talks with the UA vendor forced UACO into changing over early. It is also my understanding that SHARES is "More robust but slower, and somewhat more complex" (Same can be said of most command line vs GUI systems). Hopefully they prep as much as possible to mitigate in the short term. In the long term UACO may end up with a system that is both better architecturally, the same useability, and much cheaper.
If they have fully merged CSR operations by then it might make things smoother as well.