My interpretation of the results, purely anecdotal as I have yet been able to get full data, is that the stage list is relatively a non-factor in how well Meta Knight does. He comprises about half of the well-performing players regardless (a little less usually). What it does matter a great deal toward is the distribution of the other characters. On a conservative stage list, the other characters are not very diverse; guys like Diddy Kong and Falco do really well and eat up big chunks of the remaining placements. On a relative scale, this makes Meta Knight look less dominant since other individual characters can get somewhat close to his performance (though he's always #1). At events with a ruleset like MLG's, the remainder of the cast is absurdly diverse to the point that no one even seems to stand out other than Meta Knight. At Columbus, the only character to appear twice in the top 16 even as a secondary was Meta Knight. Even going down past that, you started to see some repetition but still incredible diversity and more characters who didn't see top 16.
Perhaps a food analogy would make this simpler. Let's say you come from a big family: 14 kids! Now it's dad's birthday (Meta Knight's birthday), and he gets a cake. He immediately cuts half the cake away and takes it for himself, and he tells the rest of you that you can divide the cake among yourselves however you want. One scheme proposed is to mimic dad's method. The oldest (Snake) takes half of the remaining cake, and then going down by age each kid repeats this. Of course, you can't cut an infinitely small piece of cake so the youngest few just don't get any cake at all. Another model is to divide the cake evenly among all of you. Of course, you can't measure perfectly so a few kids get a little more cake, and the youngest kid (Ganon) is allergic to cake so you exclude him, but it ends up pretty close. Of course, dividing that much cake among so many kids naturally means none of you get very much at all, but at least all of you (except young Ganon) get some. Which is the more balanced cake distribution? Under the first model, the oldest kid is able to have a piece big enough to kinda matter in comparison to dad's. However, under the second model, the cake is shared much more fairly even if dad's piece seems ridiculous in comparison to any other individual piece.
I'd also point out that MLG's infinite rules allow a few extra characters to be factors, and it really shows. I doubt we'd have seen nearly as much DK, Luigi, or Ness as we did if not for those rules, for better or for worse. This doesn't really affect Meta Knight, but it just continues to divide up the remaining "cake" among the rest of the cast.
