I was playing a beta world, survival (not experimental), after a while I turned on experimental features (caves and cliffs) probably 2 weeks ago.

When I saved on the prior version, I was in a house on the surface (66 +/-).

I saved, quit, ran the update. Rebooted the Xbox and loaded back into the world.

I was at height 64, bit in a deep underground cave.

I dug up and at height 115, I found the stronhold that I knew was in the area.

All chests were empty! The rest of it seemed fine. I continued to the surface and found my house and village. 

All Chests were empty (they were full beforehand), and all villagers were gone. 

The sea level was at 128, and the clouds were all at ground level.

I will investigate after the next update but assume the world is broken.

Hope this helps.