Possibly a rehash of the Aviation Week article, but the SCMP is a pretty reputable source.
http://m.scmp.com/news/hong-kong/economy/article/2121660/airline-industry-braces-china-southern-exit-skyteam-alliance
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But either way the situation is messy
BA and QF are closer to MU, although QF does have CZ codeshares
AA closer to CZ
CX with new QR investment and existing CA cross-shareholdings