Yes, Atheism is a Religion

[God of Mr. Hanky]

I don't agree or disagree. But do not these "clubs" get together for the same reason persons of similar religious beliefs get together?

Not at all.

First of all, atheism is not a "religious belief". It is the lack of religious beliefs.

Atheism has no doctrine, dogma, common text, leader. It is not even a worldview. Which are all reasons why theists do congregate in churches, mosques and temples. 

Personally, I think the idea of "atheists churches" is ridiculous, but I also understand some people, fresh from the mental shackles that is theism, may miss some of what their religion provided. A community of a bunch of like minded people congregating once a week. 

There is also something called "Sunday Assembly"

Folks gather together in large secular groups just to sing folk music, and this doesn't make them religious.

Students get together in one large classroom to learn useful facts and learn valuable skills, and that isn't religion either.

Some atheists like the comraderie of gathering together in groups. They may enjoy singing with others, or they may feel a need to be inspired by smart people with ideas on how they cope in a world made crazy with nonsense-makers.  No, not even this is religion - it's called being human!