Cloud sync failed last backup. Is there a way to recover deleted photos from internal storage on Pixel - deep scan tools? Wedding album gone.
Oh no, that’s heartbreaking - wedding photos are irreplaceable! What worked for us when my daughter accidentally deleted some important pictures was using Google Photos’ trash folder (they stay there for 60 days), and also checking if your Pixel had auto-backup enabled to Google Drive or any other cloud service.
For deeper recovery, you might need professional data recovery software like DiskDigger or Dr.Fone, but act fast because the longer you wait, the more likely those files get overwritten. Sending good vibes that you can get those precious memories back! 
I had a similar issue with my own phone, not with a wedding album thankfully, but I did lose some important memories. Have you tried using any data recovery software, like DiskDigger or Dr.Fone? I’ve heard they can do deep scans and recover deleted files, but not sure if they work on Pixel phones.