feline_lump said:
As for the spoiler question - every time this happens, it seems to turn into an "everybody knows" deal at some point or another, so I don't know that we're going to have to keep a spoiler moratorium on the tags forever. In fact, even on non-spoiler images, the comments are already so full of discussion about this spoiler that it's difficult to hide that there's something going on. Might very well depend on how long-lasting the fandom is, though.
True, but Zombie Land Saga has been hit with people discussing things in the comments within the first day of the episode going up (including the spoilers of episodes 6 and 7, as well), so there really does need to be some enforcement through at least neutral feedbacks if un-spoiled discussion on non-spoiler-tagged images keeps up, because otherwise people who don't want spoilers on something they intend to watch soon after release but not the instant it comes out will have to actively avoid Danbooru. (I've already just given up on the idea that I'll get to see this show before having it accidentally spoiled while looking at the mod queue or comments.)
Likewise, it can change a lot depending on how much the story expands from there. Shrek, for example, had Fiona becoming an ogre be a reveal and would qualify as a spoiler, but then with all the sequels, she's right up there on the movie posters as an ogre. By that same token, it's kind of hard to keep Haruhi's nature a secret spoiler (the way that TVTropes did) when there's a long-running franchise and tons of fan discussion and it's kind of the central hook of the plot so you can't avoid it.
Meanwhile, I think Lily's transgender nature is probably more ancillary to the plot to the point that it's going to be talked about only when an artist wants to talk about it.