How is there a rumored release date for a emergency driver update? Isn't it just "release after it passes the tests", or at the very least, "release after we ru

How is there a rumored release date for a emergency driver update? Isn't it just "release after it passes the tests", or at the very least, "release after we run it for 24 hours and it doesn't light the machine on fire"? Having a date implies they already have the fix and they're waiting on something else.