The Information published a story today regarding the contracts phone and other Android device makers are required to sign in order to certify their devices as Google-approved. While many of the details are, to be frank, utterly mundane (like the previously-leaked boot screen logo requirement) or things we've tended to assume, there are few pieces of information worth picking out.
First, the name of the agreement these OEMs are required to sign is called a MADA - Mobile Application Distribution Agreement. Basically, it's the Google Play contract - it's how you get Google services on your device.
New requirements include expanding the basic prerequisite that Google be a device's default search provider to also encompass voice search or voice assistants. This new requirement has almost definitely stifled the development of competing voice assistants like Samsung's S Voice, though I doubt anyone but Samsung is complaining about that.
Further than that, though, OEMs can't even change the hotword for Google voice actions, and Google maintains the right to define the hotword in its contract. Presumably, the phrase is currently "OK Google." Even the home button is subject to restriction - a long-press must launch Google Now, and a swipe up from a virtual home button must also do the same thing.
OEMs also aren't allowed to change the default webview engine on devices anymore, and the MADA states that apps must use the Google WebView Component (now powered by Chromium) when an in-app web view is launched.
The Information additionally alleges that Google signs separate agreements with manufacturers and wireless carriers (in the US, carriers are probably the more important party for MADA signings in some cases, as they dictate a fair amount of the default software configuration) regarding revenue sharing from Google Play and Search. That's certainly interesting.
Other than those little technical tidbits, though, much of the article just rehashes a lot of what we've heard and known about how Google deals with its OEM partners. There's also just the obvious and / or tedious stuff - Google has increased the number of required preloaded applications on the phone, dictates that a Google folder with those apps must be present on the default homescreen along with a Google Search widget, and even goes so far as to state a required order of apps in the Google folder. Exciting.