Normally one would expect the rankings to be more or less constant without any balancing, this is exactly the point of the article. The shuffling indicates tha

Normally one would expect the rankings to be more or less constant without any balancing, this is exactly the point of the article. The shuffling indicates that new tactics/play styles are found and widely adopted (as well as preferences are shifting) over time. With rebalancing, the shuffling should be more or less random (or at least you would see a higher "volatility"). Without rebalancing most characters which were judged as strong stay strong but players perception for some characters changes with tactics etc.. It would be interesting to not just see the overall standings but some kind of "consensus" rating (which characters are rated similar and for which characters ratings are mixed). By the way, your point also shows that SSBM has an extensive gameplay and is (if intended or not) well designed for competitive play - otherwise ratings should be more stable.