Sorry, my explanation was bad. From observation I think this is what damus is doing: Damus shows names instead of npubs, if they are loaded. As soon as Damus shows a note, it tries to fetch the metadata of the author (kind-0 events), including name, avatar and so on. So once you have seen a note of somebody the name is shown instead of npub. Recently Damus introduced caching, so this metadata remains restarts. Maybe metadata are preserved longer, if you follow someone. But I do see names of profiles which I don't follow.