The new Timeline feature for Windows 10 was made official earlier in the year, the feature was due rto arrive in the Fall Creators update later this year.
The Windows 10 Timeline features is designed to let you switch between multiple devices, this also includes Android devices and Apple’s iPhone. Microsoft has now revealed that this feature will not be available in their Fall Creators update.
Correct. Timeline won’t be in the Fall Creators Update. We’re planning for it to be in early insider builds shortly after FCU is out.
— Joe Belfiore (@joebelfiore) July 3, 2017
Microsoft have delayed the Timeline feature to another major update, this is expected in March of next year, although this could possibly change.
Source The Verge