From searching this forum and others it seems that it is not possible to use pics from CMG in Facebook. Are there plans to make this possible in the future?
There are no such plans. And it almost certainly will not go into the core code. Could be done as a plugin though. Not related to bridging. Moving to feature requests.
There is already an app that does what you're requesting. The app add a new tab that shows the whole gallery embedded, I've seen it working and it's nice. Use Google to find it.
But it's not a bridge file, just something that allows you to show your gallery on Facebook.