No, when you select "I don't know, I'll decide later", the account does stay pseudonymous. So there is a way out, it's just not easy, because you need to choose

No, when you select "I don't know, I'll decide later", the account does stay pseudonymous. So there is a way out, it's just not easy, because you need to choose a "legit" reason for not using the real name (e.g. "my channel name is for a show or character"). You can't simply dismiss it permanently. I haven't been reminded yet, though.