I actually had this exact same thought earlier! As others have said though, I don't think this will be implemented as it's not really needed. Retainers have access to jobs so they can use job-specific equipment, but since we can't change the equipment of our Squadrons (yet) there's not much need for them to have access to jobs. If Squadrons really can be used in dungeons in future patches I can definitely see them considering whether they should have access to jobs though, otherwise they'd be locked out of a variety of very important skills (Shield Oath, Regen, The Wanderer's Minuet, etc)