That depends on your client. Connect for lemmy shows a placeholder for comments from blocked instances. You can click to show the comment anyway or just blissfully ignore the high probability rage bait.

I actually like that implementation, because the obnoxiousness of hexbear users is context dependent. On posts about gardening and nolawns I’ll usually see what they have to say. On political posts, I usually regret reading their comments. So it’s somewhat nice to opt-in to comments on a case by case basis.