Part of the problem is that unless I am actively engaged with the CGL facebook feed, facebook likes to hide some of their stuff from me. Even when I go looking on their page it varies from one instance to another what they are showing. Facebook is very unreliable as a news platform in my opinion. I don't know if anyone else runs into the same problem, but I'd assume so.
I don't use twitter at all though, so I have no idea what kind of problems anyone might run into finding news there. If anyone were taking suggestions, I would suggest using reddit for news posts. You can make a subreddit that only allows it's mods to post, and then sticky any announcements you want to make to the top. I've found it a lot easier to get info from than facebook, in multiple communities in the past. Not that any of us actually have a say in the matter, but I also like the idea of an email list.