Open Ishgarde + create Ishgardian job npcs in each city state.

[Enkidoh]

I dont understand what you mean.

No job has any skills locked behind any primals post 2.0

Technically they do. The original classes stop learning abilities automatically after level 50 and from then on you only get abilities through Job quests, and because those quests move into Heavensward areas... you would need to do the storyline to gain access to Ishgard to be able to complete these quests.

And because you need to do Primal fights as part of the main scenario... thus indirectly you need to do Primals in order to gain new skills past level 50.