Microsoft had announced at Build 2017, OneDrive placeholders will be back soon on windows 10. The feature is now available on windows 10 but Microsoft has renamed them to OneDrive Files On-Demand. This new name itself describes the feature and is less confusing than earlier name as OneDrive Placeholders. Microsoft has officially confirmed that it is now available to users enrolled in Windows Insider Fast Ring which you can try out. Do mind that you must have the latest Windows 10 Insider Build 16215.
When you add your OneDrive account on your Windows 10 PC you know that you can see all your files in the File Explorer directly. But with this feature now your OneDrive files will shown in the file explorer but it will not be downloaded by default on your device. Now it will download your files only when you open it or you decide to keep it offline for future use. For getting files to be used in offline mode right click the file and click on “Always keep on this device” option which will let you download a specific file.
Microsoft will roll out OneDrive Files On-Demand for the general public with the Windows 10 Fall Creators Update later this year.