I read a good article written by someone who grew up without faith in an area where that was fairly normal. It was not until she was older that she realized it is not the experience of most folks. She addresses "when" to announce one is atheist.
I like to use the word atheist because it draws a line in the sand. I think that is important in American Christian culture. I was talking with an evangelical relative one day and I realized through things he said that he really didn't mind if people were not Christian... just as long as they understood that, in America, they were second-tier citizens. Really, you may think I exaggerate, but no... he said that "these people" just need to understand that "Christianity comes first".
I think this is why Evangelicals like Trump so much. He, more so than any previous president, is willing to use language that aligns with my relative's 2nd-tier perspective. Evangelicals (and those of similar conservative religion) see two Americas and so does Trump. When they speak of unity, they do not mean in a pluralistic way, rather they want your conversion or submission.
I use the word atheist because I like to stand in direct opposition to that. I will not convert or submit. However, I am privileged in that regard. I don't pay any particular cost to be "out". There are plenty of folks who, if they announced their atheism, could lose their marriage, their job, their standing in the community, their family relations, etc.
Think about it. In America, someone can announce that they are a serial adulterer, an absent father, a sexual predator, a bully, a racist, etc. and still be elected president.
Announce you are an atheist? You wouldn't even be considered in either party.
We still have a ways to go.