I don’t think that a game involving uncontroversial facts about the history of politics (e.g. “guess the U.S. President") would be banned under HN’s rules either.

The guidelines say:

"Off-Topic: Most stories about politics, or crime, or sports, or celebrities, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic. "

No mention of religion there, and it says "most politics" not all politics.

"Anything that good hackers would find interesting" and it seems reasonable for that to include philosophy, religion etc. and definitely an interesting web app is of interest.

This is less about religion directly and more about sharing a cool app imo.

Also, tbf, there are regular posts on the HN front page that I would consider "political". (Though I'm not bothered by them.)

I see this as the only possible logical conclusion