Sweeeeet. I knew there was a community of people digging like crazy in the chalice dungeons to see what there was to find, but I was sure they had found it all.
Probably just the former, BUT, the DLC is an actual add-on, not like, you're missing out on story (wait BB has story?) or content without the DLC. I've never gotten around to it,
Worth adding that the DLC for Bloodborne was actually intended to be two separate DLC's that they just ended up shipping as one. So it's super worth it's price point if your at all interested in it.
I read it, it only explained how there's possibly a bug in the game where you can't unlock more than 32 out of 200 dungeons unless you do a thing, nothing about the boss itself