(POST CONTAINS POTENTIAL SPOILERS)
Given the current lore, I do believe we will (one day) have access to the primals, especially considering that (SPOILER) Ifrit mentions that he feels another god's influence over you when you confront him during the main storyline. This would explain why you have the power of the echo and can speak with him directly while others cannot. This is possibly also why he spares you. I assumed he was referring to your guardian (for me, Oschon), which would be nice because they have yet to 'really' incorporate that into the game... but I could not be sure. We'll have to see... but, I'm thinking our 'summons' will not simply be entirely on a small-scale level... They might make the primals timed 'job' abilities (like the 5 you receive with other jobs) while the actual class will have elementals and other buffs. Hmm... I'm getting off-topic.
As far as the complexity of the design... if it is used, I'm sure SE will 'spice it up' to give it that extra 'wow' flare that AF has. Then again, they may keep the design and only add SMALL details, such as stitching or raised areas. As an example, if you look VERY closely at WHM AF, you can see indents and raised pieces of fabric that make it even more ornate than it at first appears to be.