it's for the official Office keyboard.
it comes wirh shortcuts to ms office stuff and was supposed to work without installing any software, so they bound them to an extremely long key combinations no one will trigger by accident and shipped the changes to all windows users.

also another fun fact: Ctrl + Alt + Shift + Win corresponds to the "Office" key, and hitting that combination will make Windows silently and automatically download and install the Microsoft/Office 365 App and launch it, even if it was previously removed