Device Preview is no longer available in this release. Additionally, the Preview CC iOS app is no longer available for download or actively maintained as of October 2017. If you have a previously-downloaded version of Preview CC on your iOS device, you can continue to use it on an as-is basis with earlier versions of Photoshop.
Photoshop no longer prompts you to import assets into Creative Cloud Libraries while opening documents. You can still automatically import all assets from an open document using the Create New Library From Document command in the Libraries panel.
The Preferences > General > Show Recent Files Workspace When Opening A File setting is no longer available.
On macOS 10.13 (High Sierra) and newer, Photoshop uses a dark title bar for floating document windows when UI brightness is set to one of the two dark settings.