This would let iPhone owners use Android Wear watches with their handset.
Why would anyone even consider that? The cost of a smartwatch is the likely main reason. Most Android Wear devices range in price between $199 and $299. The starting price for an Apple Watch Sport model is $349 for the 38 millimeter size while the larger one adds $50 to the price. Step up to the stainless steel Apple Watch and you're looking at $549 with a basic band.
Android Wear: What you need to know
This wouldn't be the first time Google added support for its own wearable devices on Apple phones. Google Glass was long an Android exclusive, but eventually, Google created a MyGlass app for iOS so that the wearable display could receive notifications and other data from an iPhone.
The Verge notes that Apple could reject any Android Wear app; certainly a possibility. However, the company allows Pebble to have a similar app so that Pebble owners can pair and use their watch with an iPhone.
There is precedent for Apple to disallow apps that have another platform name in the title, though. My guess: Google does submit an Android Wear app to the iTunes App Store but it won't have Android in the name. Perhaps the company will take a cue from its last wearable iOS app and delivers an app called MyWear.