I say this because the story this patch makes it pretty clear that the Ascians are manipulating Coerthas to be their latest piece in the "Trick people into summoning a primal" schemes like they tried in Little Ala Mhigo early in the story. My guess is that the more primals that are defeated the more Aether moves to Zodiark and away from Hydaelen, increasing their strength. The Warrior of Light is like a light casting a shadow, the stronger he/she gets the stronger the Ascians grow in turn from his or her efforts.

Also if you look at the traditional spells we have which are drawn from Aether -

Fluid Aura - Leviathan
Thunder - Ramuh
Aero - Garuda
Stone - Titan
Fire - Ifrit
Blizzard - Shiva


This isn't to say they can't add more Summons in the form of primals, but I doubt they will be presented as they have been in the past (Ie they will either be Dungeon bosses ala Diabolos or Siren) OR they can use the lore to explain the existence of things such as Alexander (Would easily be explained as another Allagan collosi/weapon akin to Ultima or Omega). Thoughts?