There are plans to do patches for most of the Captain Sim addon aircraft for FSX (excluding the 757 and 767 AFIK). How long before we see them is the "$1Million question"!
In other words, there is no time frame for when exactly they will be released. It's a case of "they will be ready when they're ready". ;)

EDIT: Captain Sim do not support multiplayer:

Q: I got some issues with your product in multiplayer/online community/server.

A: Unfortunately we cannot not support any issues related to multiplay, online communities, online server etc. because remote server connection problems may be caused by various non-product related reasons.

From: General / General (QID 1758)