I recently was playing in a relatively new world when my game crashed and when I relaunched it I had the weird corrupted chunk slice as seen in the picture attached.

A few hours later I was mining and logged off for the night. The next day I went to play the world and got the "There was a problem loading this world" bug, meaning the whole world is corrupted/unplayable. I cannot find a solution for the Xbox One version of Bedrock to retrieve the world.

This would have been devastating if it happened in my main survival world. 

TL;DR - If you see corrupted chunk slice on your world, consider backing up/copying it to try ensure safety.