This sounds weird. When CNBC broke the story a month back, I'd : 1. gone around deleting every invoice from my GMail inbox 2. Noticed it wasn't getting removed after waiting for 24 hours. 3. Reached out to the reporter mentioning google might be not deleting it properly. 4. Waiting a couple more days and calling off the alarm when google did finally delete it. I wrote about it at https://captnemo.in/blog/2019/06/01/c…
I always assume there's a backup somewhere in Google or Facebook that's old as hell but has the old emails, I would assume some of these places have cold storage options for backing up legacy data, but then again, there's the time myspace wiped a bunch of old data and nobody seemed to have cared. Surprised to this day that many other sites have shut down, but MySpace keeps on kicking.
No backup of user data exists more than 30 days there, typically less.