Glad you enjoyed it. 👆
Remember, Destiny knows 'the plan', which means he knows the story itself. Absolutely everything that can/will/does happen is in his Book -- that is his fundamental function as a character. Because of this all-encompassing knowledge, Destiny will always *seem* like he is borderline metatextual, but I don't think that is necessarily Gaiman's intent.
More than most other characters, Destiny is very much limited/confined to the concept of in-universe story... He cannot transcend the story, like a true metatextual being can.