real sara hours | pfp by @apteraclytia on twitter

The Brave New World expansion for Civ V reworked the culture mechanic, and part of that was revamping the Great Artist unit from a general creative person of note that could start a Golden Age or boost your civ's culture output to a more specific visual artist with a Great Work of Art tied to them. This narrowing of scope meant that some previous Great Artists instead became Great Musicians or Great Writers that could do different things.

As with the previous expansion, Gods & Kings, the list of possible Great Artists was also changed, and interestingly enough, in Brave New World Kafka can no longer spawn as either a Great Artist or a Great Writer. So in a sense, his appearance is mutually exclusive with anyone who appears only in Brave New World, such as Brazilian leader Pedro II.