We (for some value of "we") could do that. But it wouldn't erase all the past discussions on LW (and OB before that) that have touched on religious topics, and in practice it probably wouldn't stop LWers discussing religious topics, still less casually assuming things that are incompatible with conventional religious beliefs. (Even if explicitly religious discussion were strictly forbidden somehow, LWers would still be looking for natural causes and simple explanations, treating evolution as an important fact rather than an anti-God conspiracy, etc., etc., etc.) So it wouldn't do much to make LW readers in oppressively religious regimes safer or happier.