I see a significant distinction between authors who take active steps to conceal their identities and authors whose identities are only concealed out of public indifference. You apparently don’t feel this is the case.
No, actually, I don’t. Authors use pen names for a zillion different reasons and stay with them or abandon them or make themselves public for a zillion different reasons. As I said earlier, it’s a spectrum. Besides, what you say is more or less a tautology. All authors who use pen names are taking active steps to conceal their identities. What happens later, sometimes much later, is irrelevant to that act.
I want to share my favorite anecdote about pen names, for no more reason than I love telling it.
Ellery Queen wrote a mystery in 1929 in which the detective was named Ellery Queen and the novel was supposed to be the book written by him describing his case. That made it obvious that Ellery Queen was a pen name but nobody knew whose.
In fact, Ellery Queen were a team, Frederic Dannay and Manfred B. Lee, and nobody guessed that at all. They were prolific, too much so. They were a major example of what I said earlier, that publishers had a firm policy in the 1930s of not publishing more than two books by a given author in a year. So they created a new detective, Drury Lane, and a new pseudonym, Barnaby Ross. He was a hit as well, and nobody knew that he was a pseudonym of Queen’s or anybody else.
Both Ellery Queen and Barnaby Ross got invitations to give talks. Since this was the Depression all income was a good thing. The problem was how to do this without giving themselves away. As professional problem solvers, they had a nifty answer. They gave talks together, one pretending to be Queen, the other Ross, and would loudly debate the subject of mysteries, implying that the other’s opinions were idiotic. And they wore domino masks to conceal their faces.
The dual identities weren’t revealed until 1940, when a budget reprint of their first book was published under the Queen name, with “now it can be told” on the cover.
I have no idea of how to classify this in your terms. If they hadn’t gotten famous, then the secret wouldn’t have been made public, probably. But so what? That future made not a particle of difference in the 1930s when the books first appeared. Revealing the dual identities was exactly what their publishers feared at the time. Revealing real identities was exactly what Wilson and Cornwall feared at the time. Not revealing real identities is presumably exactly why people today are using pseudonyms today, with no possible way of knowing what the future holds. What distinction are you seeing here?
That was Wendall Wiki, in post #12. 
Fascinatingly enough, “Frederic Dannay” and “Manfred B. Lee” were themselves pseudonyms! Dannay was born Daniel Nathan, and Lee was born Emanuel B. Lepofsky.
Wheels within wheels, man.
Technically, no. Both formally changed their birth names in the mid-1920s, before they wrote their first book. Just as Salvatore Lombino changed his legal name to Evan Hunter in, I think, 1954.
Interesting. I stand corrected.