Apple today seeded the fourth beta of an upcoming macOS Sierra 10.12.4 update to developers. Their latest build is 16E175b.
The first thing I spotted was that two of the three new plists, added in Build 16E144f for Kaby Lake processors, will be removed by an installation script:
Source: Tools/cleanListSUConstructed (paths shortened).
The third one is still there:
Another thing is that /S*/L*/Extensions/eficheck.kext is being removed. Along with all the whitelists at: /usr/libexec/firmwarecheckers/eficheck/whitelists/
The NVRAM variable SkipBluetoothAutomaticFirmwareUpdate is now also removed.
Looks like Apple is preparing for a release…