What on Earth are you talking about? He doesn't talk about atheism at all in the article, which was written, by the way, for the Freedom From Religion Foundation.
I think the part Vlad was referring to was this
"I sincerely hope that the FFRF does not insist on adopting a “progressive” political stance, rationalizing it as part of its battle against “Christian Nationalism.” As a liberal atheist, I am about as far from Christian nationalism as one can get! "
Which seems entirely relevant to the article.