tl;dr: Yes, the community consensus, at least the last time I brought this up, is that a question with a small, finite, stable list-style answer is on-topic. Unfortunately, the question at issue here doesn't fit that criteria, and was rightly closed.
I agree with Pureferret, and I'm rather shocked that high-rep users would consider this a good question. IMO it falls squarely into the kind of list question that motivated the no-lists policy in the first place.
In general, regardless of the form that it takes, a question on a Stack Exchange site is expected to have a single, objectively correct answer, and that answer is expected to be valid for future users that have the same question. Obviously, that's an ideal that isn't always possible to meet, particularly on this site where retcons are almost the rule rather than the exception, but it's still the goal we should strive for.
An on-topic list question is a question that can be answered entirely in a single answer, which can be judged "right" or "wrong", and is likely to remain correct forever. For example, "How many Observers were there in Fringe", or "How many species of intelligent non-human were there in Harry Potter" would fall into that category.
An off-topic list question is any question that fails one of those criteria. In the case of the Batman nickname question, the main issue is that any answer we give today is very likely to become wrong in the near future, because Batman stories are being published constantly.
On top of that, it's going to be very difficult for the OP to determine if any given answer is correct or not, because it's any answering user would need to have either memorized, or have access to, every single issue of any comic imprint that includes Joker making reference to Batman. As @Keen says in the related meta-question:
It's not reasonable to ask a question on a Q&A site that requires knowledge of all works that ever existed, and then request a massive list of the works that contain one specific element.
Finally, there is the issue that we can't tell from the question how broad the answer will end up being. On this point, I think there is some disagreement; comments on the related meta question go both ways:
Questions shouldn't really be judged on the quality of the answers provided, they should be judged on their own merits. - @Anthony Grist
I disagree with your premise - to an extent, the answers a question generates (or will likely generate) should be a factor in judging a question - @Iszi
But it is a factor worth considering, that leaving the question open because it might not generate a huge list of partial lists as answers, means risking that it will produce exactly that. And closing a question because we don't like the answesr just feels wrong.