I also like how everyone is clairvoyant. "If they implement this, their already small player base is going to get smaller. A bunch of people will just quit." Where are you getting these numbers? In YOUR opinion, this will happen.
Many people love to pretend they have a very vast knowledge about everything in life (including video games :P), but truth is they don't know shit! XD
The battlepass did not got "leaked". Blizzard just has this battlepass concept which they are not sure about, so they are gathering some feedback before they are developing this concept further. Nothing more, nothing less.