Apple Increases tvOS App Downloads
When Apple unveiled tvOS in October of 2015, they indicated that tvOS applications could only have an initial size of 200MB, but could download additional assets up to 2GB. This functionality was done through a method called "On-Demand Resources", or ODR. The reason this was done was to allow the application to download quickly but still provide a way for tvOS applications to be more complex. For games, a prime example would be providing the first few levels of a game, and then downloading the remaining levels in the background.
Apple has changed the initial size of the application. Instead of previously being 200MB, it is now possible to have an initial application size of 4GB. These tvOS apps are still able to download additional resources, up to 20GB worth of resources.
Possible Reasons for the Change
There are likely a few reasons why Apple would do this. The first is likely due to many developers indicating that the limitation of 200MB is not enough. This could be due to users who have slower connections not being able to download all of the assets in enough time without having to wait anyway. Many users are accustom to having to wait for applications to download.
Alongside this, the increase may allow for a varying of application types to be developed for tvOS. The 200MB limitation may have deterred some developers from creating tvOS apps due to the limitation; despite On-Demand Resources being a viable option.
There is another possible reason. That reason might be to keep both tvOS and iOS in line, in terms of initial download size and the size limitation of On-Demand Resources. This is the more likely reason, given that iOS applications have a maximum size of 4GB, but can download additional On-Demand Resources.
Speculation
The last possible reason for this change is a wild one, but Apple could be attempting to begin to position the Apple TV as a gaming console. Not primarily as a gaming console, but angling it more as one. The motivation behind this thinking is that with tvOS 10, Apple has now allowed developers to require a gaming controller for their games. A possible side effect of this is that future Apple TV models may have larger options for storage.
With the size increase, the number of applications that can stored on a 32GB 4th Generation Apple TV would be reduced. If a user has six applications that are 4GB, the user's Apple Tv would be nearly out of space.
Final Thoughts
Regardless of the motivations of the size change, it will be a nice change for some users to be able to download larger applications and may ultimately lead to more tvOS applications being available, which would be a good thing for Apple.