One of the things I think about while revising and updating the holiday guides is that the audience for them is doomed to get smaller over time. It's reasonable to expect that, because people don't need the guides after they finish doing the events on characters they care about, and there's generally a few years between Blizzard's major updates. However, with the introduction of account-wide achievements, pets, and mounts, the replayability of holidays has probably suffered a bit. That doesn't mean that the content's not enjoyable, just that each successive character derives less reward from it.
This is a particularly acute problem with the approaching Lunar Festival and how one element gets a lot more onerous as the game continues to expand.