I've begun hearing this somewhere but I'm not sure where to look to confirm/deny this statement.
In Wrath, the only mounts made unavailable from a meta were the Naxx 10/25 meta mounts, and even when turning over to Cata, people can still acquire the mount from the metas from like ICC even well after the launch of Cata. I'm wondering if the drakes and birds from the current Cata raid metas will become unavailable if not completed before the MoP patch. If so, if someone could provide a link to confirm this, that'd be greatly appreciated.