Why is 3.8.3 being updated to 3.8.4 and not 3.9.2?
Why is 3.7.3 being updated to 3.7.4 and not 3.9.2?

If it's such an important update, why within TWELVE hours?

I always wondered, is there a slow on the servers right about now since A LOT of sites are updating manually/automatically?

Imagine if EVERY WordPress site updated this very instant. Could their servers handle the update?