Microsoft has shortened the recovery rollback period from 30 days to just 10 days in a bid to help free up some more space on consumer PCs. As reported by SuperSite for Windows, the company previously allowed for 30 days before previous installs of Windows were deleted on a PC, allowing those who wish to downgrade to an earlier version ample time to do so.
This has been shortened considerably to just 10 days as part of the Anniversary Update. Now should you update yourself to a more recent Windows Insider build and wish to rollback, you have but 10 days to do so within Windows 10. The reason is to help free up space on computers as noted above, but Microsoft has also explained that most of those who use the feature did so within the first week or so.
It may not sound like such a big deal to those with ample amounts of storage on their main desktop PC, but for those on devices with limited available space, this is a wise move by Microsoft to help free up some room for personal files and software.