I don't see this happening. Cross class skills are a major part of the game. By this reasoning, they're not going to allow Rogue to equip any cross class abilities since the ones in the game have their already established affinities. There are a few ways this can pan out:
-Rogue has a little something for each job, though no job would have all of its cross classable abilities.
-Adjustments are made so that jobs can pick from an additional class while giving NIN its set of classes to choose from (crossing fingers that LNC will be added to WAR's abilities)
I think it's also worth noting that currently there is only one class that is a level 15 requirement for two different jobs. NIN will break this trend. It's also worth noting that of the two jobs that require CNJ, none of them have exactly the same skillset. Remember that SCH can use Cleric Stance whereas PLD cannot.
