Yes, it is a possibility but it's early in the game right now. I wouldn't consider US' place in *A to be as precarious as BD or JJ. The way they are, US isn't leaving *A but if (and when... these things take a while) the merger goes through they'll almost certainly go to OW. They even recently bought the domain name "OneworldOneairline.com" in preparation for a possible merger.

If you're really concerned about US' long-term future in *A I suppose you could go with UA, which is the other good *A FFP for "cheap" redemptions.