Earlier quoted context omitted.
This was intentionally pushed by his campaign precisely for that reason - to get all the dirt out while they can control the spin. Better to burn the story now that he’s “just” a primary candidate.
I mean that would make sense but source?
So the reporter interviewed him first then went to the other members, who somehow "flipped" uncharacteristically (unlike they had done before). The book will be published in June but the reporter decided to start banging the drum much earlier, which is more convenient for O'Rourke than for his sales (he's basically given all the good bits away already). If he wanted to maximize exposure and sales, he would have waited for the eve of a primary; like this, it helps O'Rourke get the dirt out early.
Speculation? I'd just call it realism.