I'm not sure I've ever heard that sort of thing called a churchkey.
While to me, that is absolutely its name, and any other name for it describes only part of its functionality.
My daughter grew up hearing me (and my mom) call it a churchkey, and sent me the funniest little voice message via WhatsApp yesterday, decrying the ignorance of the others in her dorm and thanking me for educating her properly. I did a survey of my office, and among the native-American speakers, one other firmly agreed with churchkey and the other two had never heard the term.
I'm wondering now if it's a regional thing, a generational thing (with some trickle-down), or what.