Good for them. The whole point of this 'break the record' thing is to engage the fans in the game and honor their contribution. Football is great in that fans can genuinely alter the game itself to some tiny degree, whereas I don't really think it happens nearly as much in other sports. The Chiefs, by all accounts, have a great fanbase, an incredibly loud stadium, and deserve to be recognized as such.
I think that going for it so quickly after Seattle broke it is going to make the whole thing seem rather tawdry in the eyes of the rest of the nation, which is a shame. No one likes needless one-upping and copycatting. Which is why I hope Seattle lets it stand for a while. I don't think anyone doubts the passion of Seattle fans nor the intensity of our home-field advantage, and I don't buy for an instant that Chiefs games are louder moment to moment than Seahawks games. But there's no real way to prove that, and the Chiefs are probably the only other fanbase in the NFL that should be compared to CLink anyways.