My main gripe with that is that there is no guarantee a player is any good if he beat one or two others in a game no one else is interested in playing, and his opponents just learned the rules a week in advance. Most Chess variants are pretty much alike, and if you would be good at one, you would be good at many others. 'Superchess', for instance, is actually a family of variants that (much like Musketeer Chess) use different substitution pieces. So one year the 'championship' can be played with a certain set of pieces, the next year with another. Yet the same person, who happens to also be a FIDE IM, tends to win it.
I have been watching one of these games going on at the chess.com, and the play was awful, hardly above the level of a random mover. One player didn't even seem to be aware that when an opponent trades a piece, it is usually good strategy to recapture. Being able to beat such opponents isn't really worth mentioning. How strong can play really be in a variant where the rules are only decided upon days before the match? If the players were all super GMs, perhaps I would believe it. If they are rated, say, 1500 at orthodox Chess, of which they have known the rules incredibly much longer, well....