Happened to me and my friend as well. We play on Xbox one. Fortunately i had already heard of the issue because it happened to my friend first, so i lost nothing of importance because I already took precautions.
Dont really feel like playing until issue is resolved :/
This happened to us on realms.
My friend had it happened just playing on his xbox.
Mine was working fine first day of the update, but when i switched to my phone the next day it was wiped.
I can tell you one thing i found strange was when i left the realm, the first night before everything was wiped, instead of saying the normal saving game message it normally says it instead said generating world.