Is it really the end? *Spoilers*

[Cilia]

The introduction of the porxies (to cure tempering), warding scales (to prevent tempering), teaching the Eorzean beast tribes (and Kojin) proper creation magics to call forth their deities instead of the corrupted summoning arts taught by the Ascians (so they don't want to temper in the first place), and improving relationships with said beast tribes so they're not openly antagonistic anymore (so summons are far less frequent to never) basically tells us they are done with primals as a big antagonistic force.

Given all the souls (aether) that made up Zodiark and Hydaelyn have returned to the Lifestream, it may or may not be possible to call them forth again. It wouldn't be the original / real one though, since the only living person who's seen Zodiark is the PC and the only living people who've seen Hydaelyn are the ex- but not really ex-Scions, none of whom have any intention of doing so. Without an astronomical amount of aether (like, the Mothercrystal's worth) you'd just get a wimpy simulacrum anyway.

[Jandor]

The introduction of the porxies (to cure tempering), warding scales (to prevent tempering), teaching the Eorzean beast tribes (and Kojin) proper creation magics to call forth their deities instead of the corrupted summoning arts taught by the Ascians (so they don't want to temper in the first place), and improving relationships with said beast tribes so they're not openly antagonistic anymore (so summons are far less frequent to never) basically tells us they are done with primals as a big antagonistic force.

If I recall correctly the Loporrits did the actual creating, the beast tribes provided the templates and the aether.

We've never seen any of the modern races use proper creation magic, it comes across more like a lack of ability than a lack of training. Like creation magic is to us what regular magic is to the Garleans, it doesn't matter how long you spend with Gaius teaching him to cast Cure I or Fire I or whatever, he simply cannot do it.