How to implement new easter eggs - Community hide and seek

I really don't know if this is possible, so this is more like a question than an actual realistic idea: Is it possible to create a new feature that is difficult to people that can't directly access the game code to find out? If true, then that's how to make it.

However, independently on if this is possible or not, these new "side features" could simply be featured in the game without having it in the change log, instead just saying this: "New Easter Egg Added".

The lava chicken disc could be used as an example: Have players figure out what and how to get the new feature. At the end, the whole Minecraft community starts to Egg Hunt.