> Does a change being accepted into master equal it becoming live in production at your company?

Where I am, and at other good companies that I know of, "a change being accepted into main" equals processes being automatically started, that progress it through further environments and test suites, that if they all go well, result in "it becoming live in production" with no further human intervention.

So you oversimplified, but it's a qualified yes.

Continuous deployment is a very safe and productive way of working. It encourages small batches of change and thorough automated testing. If you find it "ludicrous" that says more about you than anything else. There are books on the subject if you're interested.