All of that is correct, but, it does not mean that suggestions cannot be made. So, the article linked here mentions their suggestions, I mention my suggestion, etc.

Yes, private conversions about contributions to free software projects are possible and are sometimes desirable. But, messages on the official channels for communications should normally be public; people can (and should) of course still use their own private communication as needed, too, but does not mean you cannot have a public one too.