At least in the mobile app this (showing of posts that should be filtered out completely) seems to occur when those posts get loaded after tapping ”Load missing posts”. So it’s like the filters don’t get applied to posts loaded on demand: I just had one shown to me earlier with the ”matches filter”, ”show anyway” preamble, but now that I went to check the timeline on the same device again, said post was now filtered out completely. (It hadn’t been deleted in the meantime, I checked.)

(I couldn’t remember if the example in my web UI screenshots above was similarly loaded with ”Load missing posts”.)