"Citadel" is a name that makes headlines, for better or worse. Ken Griffin hasn't exactly lived his life in such a way as to avoid the limelight. But you're right, this is just the sort of thing that Citadel and similar firms do once in a while, when the opportunity arises.

(Spicier claim: When Citadel bailed out Melvin at the hype of the GME craze, that was also just business as usual, not a conspiracy as the redditors believed.)

Another way to parse it when they put "Citadel" in their headlines, is that they're trying to communicate to knowledgeable investors that there's no need to panic. The book is in experienced hands now, with enough capitalization to weather any further attacks, and the contagion probably won't spread.