I mean he's not wrong, but also not really the same thing. Gboard does send a substantial amount of data about the things you typed to google. It is supposedly anonymous, but they do this to get anylitics, and they use this data to improve the suggestions given to you.
There has been at least one article where someone intercepted the data leaving from Gboard and found it's either unencrypted or just hashed into something like base64. This was a while back so things hopefully changed.
While google does try not to phone home users passwords, how can you tell what is and isent private?
I disagree, what we really need is for these chat apps to use an open protocol