If you create any world in the caves and cliff experimental no matter if it's in creative or survival the bonus chest won't show up. It's still in experimental I now that, but I figured before it was completely done it should be known about. I have tried it multiple different times in the different game modes and difficulty, and it won't show up. I'm not sure what a screen shot would look like to prove this.

If you stay in 1.17.10 the bonus chest will show up but if you try to do the caves and cliff version it won't.