They have said previously that the FC airship stuff will be designed so people outside of the FC can be invited along. Depending on the numbers the new content needs it won't be surprising to see FCs recruiting people through Party Finder and such to fill out their teams before heading out on missions. Small FCs can make alliances with other FCs to do the content and it has potential for players who aren't in an FC to potentially get recruited.

Sure it's open to exploitation and abuse but on the flipside it could be very good for community building. My FC already shares a linkshell with a couple of others for raiding purposes. I could easily see FC alliances and Sky Island Linkshells forming around such content.

Being blunt, this is a reality of breaking the mold on content. There needs to be a trade off. People are always asking for new things on this forum. The thing is, something always has to be given up for that new stuff to be made.