AT is not yours - it belongs to Blue Sky pbc. You can link your own domain to it, but the user interface belongs to Blue Sky and they will block you if they want.
This article has nothing to do with the Bluesky lexicon or with the bsky.app AppView.
What does “they will block you” even mean: this article is talking about hosting your data on your PDS and presenting it on your domain.
This is, like, the entire problem ATProto is designed to solve.
Sure, Bluesky can block you from showing up in Bluesky the application. But if they do, you can still host your own content (as is being done here) or access it via alternative apps (like Blacksky).
This is like saying that "RSS isn't yours because Google Reader can block you."