It appears they already have ad approvers working around the clock, because I've had ads approved with timestamps in the middle of the night, and a support rep confirmed this when I asked. So if they're going to shut down our ads at night and on weekends, why don't they at least provide email and phone support on weekend days?
I've wondered about this before, but I had an ad for a high-CTR ad group suspended on Friday afternoon (even though it had been suspended earlier in the week, I emailed support, they ascertained there was no problem, and re-enabled it). It's pretty aggravating that there's no way to get hold of them till Monday morning, and I know others have expressed the same sentiment here.