The 5.3% unregistered is including the fallback. Only 50% of EOS are in registered accounts right now. This means 50% has not registered yet. Using the fallback is fine, but you are missing out on airdrops! Many of them are based on the main Snapshot, so basically this means half of all tokenholders are missing out on airdrops.
It's worth repeating to people that you should definitely register!
RE: EOS Token Swap. EOS launches in 3 days are you ready? How can I check if I have completed registration?