It was Pon Farr Night at the Vulcan Night Club on the holographic facsimile of Star Fleet Academy that Species 8472 was using to practice being Federation citizens. I think it makes sense that, if they're planning to impersonate any Vulcans for any length of time, they'd want to get their agents practice at simulating Pon Farr. Especially if they're going to simulate it accurately, so the agents will actually have to experience the urges.