I don't think Flynn "includes absurdity." He says he has faith that "absurdism" (i.e. naturalism) is irrelevant even though he fears he might be wrong.

He may avoid exoteric anthropocentrism, in which case his "theism" would be illusory since it would amount to atheism or to some naturalizing or objectifying of the First Cause.

I'd add to your second paragraph that religious faith is like the suspension of disbelief you need in entertaining a work of art. So religious folks should be more concerned with aesthetic standards in evaluating their treasured myths (fictions).