That is correct, we do not have an "official" instance or an "official" magazine. What follows now is MY OWN opinion, other community members might think differently.
Mbin is aiming for a federated and decentralized social network, I think the whole point of the fediverse is that there shouldn't be one main instance, right? Feel free to create a magazine where ever you want! Isn't that the beauty of activitypub? Maybe the idea takes some getting used to.