In his routine developer updates, the game’s director Jeff Kaplan explains why Overwatch PTR isn’t possible on the PS4 and Xbox One version of the game.
The biggest reason for this according to Jeff is that all patches on the consoles need to go through their respective manufacturers first which makes test patches really difficult to form and implement.
On PC however, that is not the case as Blizzard can simply implement the test update on their own Battle.net client where players can try them out through the Overwatch PTR client.
On the PC, we run on Battle.net or the Blizzard [Entertainment] platform which is something we wholly own and control here at Blizzard, that means patching it as frequently as we want is very easy for us, and we incur any of our own risk to our system.
In the case of consoles, each patch needs to first go to Microsoft or Sony depending on the console and it is then certified by the company which adds extra time to deployment process, time which can be used to test and further develop the same update.
However, according to Kaplan, console players should not be disappointed by this or feel left out because the open ended structure of the platform and testing on PC means console players benefit in the long run.
All the feedback which the PC players provide is heavily weighed by the developers before being implemented on not only PC but also consoles so as not to unbalance the game for consoles where movement and aiming is very different from PC’s mouse and keyboard.
This Overwatch PTR testing on PC ensures that all the crucial updates are deployed at the same time on all three platforms.