According to VG247 (via Charlie Intel), the change was confirmed by Treyarch in a Black Ops 3 live stream focusing on eSports.
This might explain why Call of Duty debuted on Sony’s stage at E3 instead of Microsoft. Sony “really wanted” the partnership and landed a deal to get the Call of Duty: Black Ops 3 beta and DLC first on PlayStation 4.
It appears Sony is heavily investing in the PlayStation 4 eSports portfolio. In addition to competitive Call of Duty, Capcom decided to make the switch back to PS4 for remaining Ultra Street Fighter 4 western Capcom Pro Tour events.
In other Black Ops 3 news, a new system allowing one player from each team to ban or protect any score streaks, weapons, specialists, or abilities is being introduced into multiplayer.