I just downloaded and installed iOS9 public beta 1 on my iPhone 6.
I opened the new Wallet - at first it seemed to be frozen. Then I realised it was downloading hundreds of long forgotten Passes!
I've been developing Passes for Passbook since 2012. I've created, installed and deleted > 1000 passes.
I've used many different iOS devices for testing over the last 3 years.
Long ago I switched off iCloud sync for Passbook. I only wanted to see my latest passes on my latest device.
When I installed iOS9 public beta 1, I soon discovered that iCloud sync was set on by default. This is why all these old passes were being reloaded.
So I switched it off.
And started (slowly) deleting the unwanted old passes. (oh boy is this slow in beta 1!)
But shortly after each Pass was deleted they kept reappearing!
It seems that switching off iCloud sync doesn't work??
And deleting a Pass on one device doesn't get noticed by iCloud - it just puts it right back there.
Not sure if this is a bug or a new feature - but I want to delete these old passes!