It seems that only one Siri remote can be paired with the Apple TV 4. So any additional remote you have can only serve as a backup.
I'm still at my company here in Asia so I will not be able to test it until tonight, by then people in the States or Europe will also get theirs
I only ordered the 32GB version because I can't figure out what will I do to fill up the storage. I will probably stream by videos from my NAS anyway.