Yup. The *entire book* is a setup to the Dracula Saves the Universe punchline, except that Dracula isn't in the book until the last ten pages which means the punchline kind of falls flat.

(And yes, the excerpt blurb thingy exposes the ending. It doesn't SPOIL it, per se, but it's a bit of text from way late showing the aliens panicking over the new human superweapon thingy that they don't understand.)