I wrote to support and this was the reply:
"I was happy to look into your request and regret to inform you that we are unable to provide a definitive delivery date for the Google Pixel 9. Google would like to start delivering the products from calendar week 37, but unfortunately exact dates and quantities are not yet available."

Having pre-ordered, I saw my initial delivery date: 22.08 being pushed back to 26-27.08 and then shifted by another 2 days the two days following today more information.
I've never seen anything like this for a pre-order, it looks like a badly managed Kickstarter or even a scam...

Ordered pixel 9 pro 512 GB on the 15.08 delivery date still unknown even though it was initially for beginning on September.