As with any new smartphone (but especially with Apple), the iPhone 8 is generating rumor after rumor. This newest rumor, however, rocks the boat a bit, as BGR reports that the iPhone 8 may release at Apple's standard time in the fall, but the 3D camera will be pushed to the 8s.
The 3D camera on the iPhone 8 has been rumored for quite some time. the specialized camera would turn the phone into an AR-capable machine, allowing developers to explore the potential of mixed reality, similar to the way Android devices powered by Google Tango have worked for a while now.
The 3D camera would also bring iris scanning to the iPhone. The Samsung Galaxy S8 saw the return of the iris scanner from the failed Note 7, which provides a fast, secure way to gain access to your smartphone. For some time now, the rumors suggested iOS users would get to experience the swiftness of unlocking a phone with your eye, but if the report is to believe, they might have to wait for a future iPhone.
BGR cites Needham & Co. analyst Rajvindra Gill, who, after speaking with James Wong, COO of Truly Holdings, said this about 3D camera manufacturing:
Truly noted that they did not believe that Apple would release the iPhone 8 with 3-D sensing this year and would likely wait until [the second half of 2018] for the iPhone 8S to release the technology due to potential delays in product assembly. The company believes that Chinese OEMs (Huawei, Oppo, and Vivo) will likely introduce the technology before Apple (between when Apple announces the tech and a product hits the market) in the [first half of 2018].
If this is true, that means Apple may be one of the only OEMs to release a phone with this technology in 2018. What these manufacturers plan to do with the 3D cameras is not specified, but Apple has the potential to fall behind in iris scanning, and possibly AR integration.
It's important to remember, however, this is still speculation. To know what Apple plans to release and when, we will just have to wait.