in 2018, Facebook told Vox that it doesn’t use private messages for ad targeting. But a few months later, The New York Times, citing “hundreds of pages of Facebook documents,” reported that Facebook “gave Netflix and Spotify the ability to read Facebook users’ private messages.”
Surprising? No. Appalling? Yes.
No, WhatsApp backups are e2ee even on GDrive, although I disabled any cloud backups ages ago, and prefer manual database copy/paste syncing.