There's no special arrangement. The only issue is clarifying what content is welcome vs. unwelcome on HN. simonw's content is obviously welcome, and this ought to be obvious.

> I think people would be less mad

People aren't mad about this. The vast majority of this community values simonw's contributions, which are well within the sweet spot for material on HN. That's why his material gets upvoted, as minimaxir (no friend of astroturfers) has pointed out elsewhere in this thread: https://news.ycombinator.com/item?id=46451969.