You're able to disable the pin feature to prevent that data from being saved though, so it definitely isn't a requirement.
I'm also not sure where you've read that they collect the contents of messages, because as far as I'm aware they still aren't doing that and I can't find any info online that indicates that they are (other than their secure backup feature that's opt-in only I suppose)
I'm also not sure where you've read that they collect the contents of messages, because as far as I'm aware they still aren't doing that and I can't find any info online that indicates that they are (other than their secure backup feature that's opt-in only I suppose)