First, I'd like to ask the author to weigh in as well. I'm curious as to what led him to ask this question.
For the answer, I'd push it. It doesn't really matter to me one way or the other whether life exists or doesn't exist, and therefore, since I tend to like to push buttons, I'd push it since there would be no compelling reason not to. Life, or consciousness, is merely one attribute of our universe, and there are many others, such as mass, gravitational pull, and magnetism. None of these attributes has any value to them in any moral sense. We like to assign meaning to everything, but there is none. These things just exist, that's it. There is no more meaning to life or gravity than that.
So, heck, why not? I like pushing buttons, especially if it looked like an elevator button.
How would you appreciate pushing the button if you pressed it? No one would know you pressed the button. You wouldn't even be able to know the effects if it worked. What if the button didn't work and you were arrested for attempted murder. Your best bet would be to leave the button and tell no one where it is.
The only way we can appreciate mass, gravitational pull, or magnetism is that we have consciousness in order to understand it with. That makes consciousness the most valuable thing that there is. I would not push that button unless the alternative was that we would all fall into a dreamless sleep for eternity and there was a known afterlife where we could keep being conscious after the button is pressed.