To date only Broadwell hardware has enabled frame-buffer compression by default. Earlier generations of Intel graphics hardware have had FBC support but it remains disabled by default due to various bugs and hardware issues. There have been several attempts over time at enabling FBC going back to around Haswell, but it's never panned out for keeping it on by default. But now Broadwell has been riding FBC by default and for Skylake+ it appears to be in good enough shape to flip the default switch.
Back in December I wrote that Intel May Finally Enable Framebuffer Compression By Default For Skylake+ while today that drm-intel-next work officially landed in DRM-Next. So unless any big regressions come up in the weeks ahead, that DRM-Next code will be merged into mainline Git and hopefully remain on for Linux 4.11.
The code landed in DRM-Next today via this pull request. Aside from flipping on FBC by default for Gen9 graphics and newer, there were also some fixes, documentation improvements, and other clean-ups. There was also a drm-misc-next update that landed.