Microsoft has recently updated the Surface Pro 4 Update History page to mention a series of firmware updates which originally rolled out on September 14th (via Neowin). The updates are mainly focused on support for the new Surface Pro Type Covers, and you can read up on what has changed by checking below:
September 14 release:
The following updates are delivered to Surface Pro 4 devices on Windows 10 Anniversary Update 1607 or later, that attach the new Surface Pro Type Cover and the Surface Pro Signature Type Covers.
- Surface Fingerprint Sensor – Biometric device 2.2.11.0: Enables support for Surface Pro Type Cover and the Surface Pro Signature Type Covers.
- Surface PTP Filter – HID: 1.0.173.1 Enables support for Surface Pro Type Cover and the Surface Pro Signature Type Covers.
- Surface Pro Type Cover Integration – HID 1.0.2.0: Enables support for Surface Pro Type Cover and the Surface Pro Signature Type Covers.
- Surface Smart Cover Backlight – System device 3.0.0.0: Enables support for Surface Pro Type Cover and the Surface Pro Signature Type Covers.
As always, you can check in Windows Update to see if these latest set of updates are available for you. Microsoft lists that the firmware updates are mainly focused on compatibility, with no performance, battery life, connectivity, security, or reliability improvements in tow.