There is a profound misunderstanding of what's going on.

If they were to engage emergency maintenance, all it would accomplish is nobody would play the game. It would not speed up the timetable on the fix, because the fix is being built on a copy of the game that's not live. There likely will be an emergency maintenance once the fix is built, tested (with all hands on deck to test the fix quickly and thoroughly) and then the move the changes to the production client.

So, until the fix is built, no - best thing to do is what they've already done - throttle the instance so that it doesn't crash the servers, let some people through and other people play other components on the game while they work on the fix. There's just no way to accurately gauge how hundreds of thousands of people will do on a server, and usually not enough money available to make the fix in anticipation even if it is seen ahead of time.

I'm beginning to think some basic IT courses should become a required course in school these days. Just to understand the workflow on how the programs people use every day works.