Nope, it's not a belated April Fool's prank. Samsung really has started updating the Galaxy Note 4 to Android 5.0 Lollipop in earnest. We saw the update going out to multiple regions earlier today, and it is now rolling out to devices in India as well. The Indian variant sports model number SM-N910G, which means the same model in other regions could also see the OTA arrive in the next few days.
You know what to do. Check your Galaxy Note 4 for a notification, or head into the Settings » About phone » Software updates menu to force it to show up manually. Well, stop reading and get down to it folks, this is the day we were all waiting for!
Thanks, Armeet!