Thanks for the tip. I installed it as well and it seems to be working. Link for the post where 16299 manual package download links can be found...
Windows Server version 1803 will be generally available on May 7. I think we can get new working dedup package for Windows 10 1803 from there.
I can confirm this. Just upgraded to 1803 and dedup doesn't work anymore. This was expected. Hope that someday Windows 10 has native dedup.
This is the only thing that is currently preventing me from upgrading Windows 8.1 to Windows 10. I need the dedup because of VM's stored to my SSD...