14 DAY TRIAL // Right after announcing that the iOS app-slicing feature is back, Apple has also published an entry on their Developer News website saying that the development sandbox environment will be removed from all iOS and OS X versions.
As the Developer News "Game Center Sandbox Update" entry says, "At WWDC 2015 we announced that the Game Center development sandbox environment would be turned off to simplify game development and beta testing. Starting today, the sandbox will no longer be available."
Moreover, on all devices running OS X or iOS, all pre-release game development will take place in the same server environment used by released games.
This means that pre-release game versions can be tested within production environments, using the entire player base of the game, and not only a limited set of testers like before.
Moreover, by removing the Game Center development sandbox, Apple has effectively merged the pre-release and production server environments, eliminating any previous differences between them.
The elimination of the Game Center testing development sandbox also comes with its share of side effects
There are also downsides to this change, besides the more streamlined development process it brings. For instance, developers have to isolate pre-release features like achievements and new games using separate pre-release accounts for testing and controlling which Game Center users can become friends with those accounts.
Apple has published a full description of what the Game Center development sandbox removal means for developers and what side effects they should be aware of.
However, the bottom line is that, by merging the pre-release Game Center sandbox server environment with the release environment, Apple has greatly simplified the update testing process for all iOS and OS X developers that had to deal on a daily basis with separate testing environments while working on their Game Center-aware games.