I would also be very interested about Sailfish OS running on Pixels. I know that the Xperia are not the only devices where Sailfish runs, I ran it on a Fairphone for example.
The only thing I found while searching on internet is SailfishOS on Google Pixel 3a · GitHub but it’s quite outdated and without any instructions so I was not able to go further.
The other solution to have a degooglized phone able to run Android apps is to run https://e.foundation but this is a cleaned Android, not a Linux OS, so I would definitely prefer Sailfish.