It depends on how much you care about staying in *A. There is a good chance OZ would end up leaving *A at some point unless it remains a standalone carrier. If you earn status with OZ and are ok with whichever alliance it ends up with, then keep earning at OZ. However, if you have a strong preference for *A, then you might be better off earning status with another *A carrier from now on.
LAX
Another problem is that currently, Korean Air only has one level of non-lifetime status that only gives Skyteam Elite. While Skyteam Elite has more benefits than Star Alliance Silver, it doesn't include lounge access or priority baggage handling that you would get with Star Alliance Gold. You need lifetime status to get Skyteam Elite+ that would be almost comparable in benefits to Star Alliance Gold with the exception of no lounge access on US domestic flights.