It's doubtful that this was unintentionally released hours after Google makes new announcements about its Nexus devices. A classic 'steal-the-thunder' move.
I think Google still ends up getting more press, since their releases are more interesting, but it's not a bad play by Apple.
Google made their announcement the day before the Apple event strategically.
Apple 'leaked' this new info to try to steal some of the attention from Google, and get people talking about what else they will reveal at the event tomorrow, thus shifting the conversation back to Apple.
None of this happens accidentally. It's all very well-timed and follows the classic playbook for "crashing" your competitor's news.
If the Nexus devices were available for pre-order today, I would be inclined to agree with you. However, since they aren't available for pre-order until the 17th, the day after the Apple announcement, then I doubt Apple is worried. Apple knows full well that they will dominate the new tomorrow.
I think Google still ends up getting more press, since their releases are more interesting, but it's not a bad play by Apple.