Contrary to what Eidos Montreal originally stated last year, Deus Ex: Mankind Divided will not launch on PC with support for DirectX 12. Instead, the game will be released on August 23rd with a DirectX 11-only engine, and DirectX 12 support will be patched in at a later date.
According to a recent Steam post by the developers of Deus Ex, the team has "some extra work and optimizations to do for DX12", which is why the API won't be supported at launch. Instead, the developers expect to release a patch that will introduce DirectX 12 support in the week of September 5th: two weeks after the game's initial launch.
Deus Ex: Mankind Divided was expected to be one of the flagship DirectX 12 games, using the brand new Dawn Engine that has been built for modern gaming hardware. The title is expected to include a benchmark that can be used for evaluating the performance differences between DX11 and DX12, although this won't be possible until September.
It's worth noting that Mankind Divided is an "AMD title" that falls under the company's Gaming Evolved program. It will include TressFX Hair 3.0 for realistic hair simulations, although this particular effect runs well on both AMD and Nvidia hardware. Judging by early footage, the game is set to look visually stunning as well, provided it doesn't succumb to the dreaded 'downgrade'.
The good news is that a lack of DirectX 12 support won't delay the PC version of this game entirely. Deus Ex: Mankind Divided is still scheduled for release on August 23rd on PC, Xbox One, and PlayStation 4.