I am confused, I don't think Damus works that way, at least not my current version (TestFlight). Damus tries to load every avatar as soon as you see a note from this npub. Those avatars are cached (quite new feature), regardless of follow-status.
Discussion
It’s the @ mentions in replies that are showing truncated npubs. I haven’t seen any unloaded avatars.
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.
Cool. Yeah that makes sense. Caching is a massive improvement btw. 🙌