Microsoft just flipped the switch to send the Xbox One July Update to customers. The July Update (version 1806) is part of the Redstone 4 development branch, which is analogous to the April 2018 Update on the Windows 10 PC side of things.
The July Update brings support for FastStart, which we first discussed last month. According to Microsoft,

Source: Hot Hardware – Xbox One July Update Lands Bringing FastStart Feature For Games