As another one who dislikes WhatsApp these day and defend Telegram I think we should still stick to the facts instead of going down to this level: I've seen no

As another one who dislikes WhatsApp these day and defend Telegram I think we should still stick to the facts instead of going down to this level: I've seen no credible or verifiable claim that Facebook currently has access to the keys. That said: credible and preferably verifiable sources are very welcome. However, depending on your threat model WhatsApp might still be a huge problem, and this is public information so you can verify it for yourself: If anyone you communicate (or you) enable backups in WhatsApp, any chats that person is part of is uploaded to Google as unencrypted data, i.e. I believe the upload channel is encrypted but it is stored in a way that everyone who can force Google to give them access can read them. Which means that you group chats might very well be readable to Google and everyone they have to obey without you even knowing.