"Open letter" is just another way of typing "Unpopular opinion".. and the only way to properly deal with these threads is to ignore them.
I take it as the following:
This is a message from the Queen.
I got something more important to say.
I want to write you but I also want to let others know what I write. In other venues people think it gives them additional leverage doing that vs a private letter.
FWIW this is an open forum and we're all writing open to Larian and everyone else.
It feels snobby to me even if that isn't the intent.