OP, about the time when SE do the patchs and maintenance. You must be forgetting a simple and little fact:

All the devs are Japanese and they have normal work hours.

Like any other job in the planet they probably work from 9 am to 6 pm (jap time). So it isn't rare that they want to do the important and risky stuff when all the dev are there to fix if anything goes wrong.

At the end they are human after all and need to rest, eat, go home, have fun, etc. They probably won't do anything on jap prime time cause that would mean extra hours at work for all the dev team.

Next time OP, chill out a little and think about other ppl.