That post was a bit before the new redis clustering in 3.0 (http://antirez.com/news/79 -- Redis cluster, no longer vaporware). Wonder if anything has changed.
The announcement page you linked to doesn't let me copy any text on iOS, but he's basically saying that if you get a partition and resolve it, the merge algorithm used is prone to data loss.
I don't know if Redis Cluster has improved since.