They probably submitted an early build a while ago and set the release date to whatever day they want it to go live. That way they can just publish the update, which doesn't require the same level of approval, and it will go live without any delays from Google.
At least that's how a lot of folks do it with iTunes. I assume they use the same technique with Google Play.
Although the TiVo app is also on the Amazon Market, so they'll need to update it there too if they plan to support Kindle Fire devices for streaming. (The 2nd gen HD and HDX are running a new enough build of Android)