It doesn't matter if it's not new information or if the companies knew about it or not. It's something that should be done to avoid screwing people over. Users don't always know about this stuff. Before publishing a tool that makes it so easy to exploit users info it's a common practice to inform the companies related ahead of time in case they are motivated to fix this (such as github did) and perhaps the users so they can have heard about it before everyone has it and they are still logging in like this.
