It might be like this:
Finish patch at 2AM GMT = 11AM JT.

If there is a problem, then they have all day to fix it.

If it was:
Finish patch at 5PM JT
The it is already time for them to go home rather than stay and fix it.

This way ensures that the people who need to be around to fix things will be there, rather than telling them they can not go home that night.


Today is good example: They are now fixing it during Japan Prime Time (rather than having them work at 2AM their time to fix problems).

Perhaps in future they can offshore to USA or UK to help fix these things. But now I do not think they plan to do this.