Please read carefully the full text:
"Most players won't be affected by this change as to get below 50% you would need to play around 60-70 battles in a day"
Where stand that you start by 100% ? I cannot found this.
If you play 60-70 battles a day you will be affected latest at the second day.
I think really that nobody understand this sentence in this way you (want) understand him.
Why you cannot just say: "Ok this was not correct - we will publish a correction / clarification" ?