It seems to simply be a community center for atheists that is being called a "church." I'm curious why do you think it's strange?
I guess I find it strange because the general context in which the word "church" or "temple" is used is when it is defining a very particular religious gathering place. I guess you could say that the part I think is strange is the word choice of the article. But I think a "gathering place" for atheists can be a step forward in their own "culture."