Ask HN: What metadata does Whatsapp collect from its users?

I recently noticed a change in my Android Whatsapp app in that sentences are now automatically hyphenated. With Whatsapp being a Facebook company, and given FB reputation, I am wondering if this could be a way for FB to get at the text I'm typing, before it is encrypted and sent on its way to the recipient (just like you unwittingly do to Samsung partner when you have text suggestions on, and using your Samsung keyboard)? Maybe I am overly suspicious, and probably this is some local code doing the hyphenation, but you never know these days.. I am considering switching to Signal anyways, but the small user base is still a bit problematic for a connected person :) But Whatsapp is probably already collecting lotsa personal (meta)data regarding the content of my messages, like when you include a URL and the bookmarklet is generated. Makes me uneasy.. Anyone in the know?