While recently searching GIGABYTE's website for BIOS updates for my X99 motherboard, I came across a new F20 BIOS for the X99-SOC Force, an update that brings support for a new and unreleased Intel processor.
GIGABYTE released BIOS F20 on 1/12/2106 for its entire X99 lineup, which supports a mysterious "2016 Q2 coming new CPU," as quoted from the website. Looking at Intel's roadmap for 2016, the next upcoming X99 CPUs will be based on the Broadwell-E microarchitecture, which has been highly anticipated by those who want 14nm on Intel's high-end platform. GIGABYTE's posting of this new BIOS reaffirms rumors and claims that current X99 motherboards will support Broadwell-E CPUs.
Looking at other motherboard vendor's sites, we could not find any hints of updated microcode for Broadwell-E support, which is not unusual given that Broadwell-E is not due for many months. Broadwell-E CPUs will work with current X99 motherboards as long as the X99 motherboard has been updated with Intel's latest microcode, so it is safe to say that if a motherboard is not shipped with Broadwell-E supporting BIOS versions then users might require Haswell-E CPUs for flashing. Releasing the BIOS so early before launch provides ample time for users to update their BIOS ROMs in anticipation for Broadwell-E CPUs, and so far, GIGABYTE is the only manufacturer providing Broadwell-E BIOS support.
GIGABYTE usually isn't too loud about BIOS updates, they recently silently updated their BIOS lists with updates addressing non-K overclocking and a Prime95 bug fix.