I still think Emet calling Zodiark and Hydaelyn primals was a deliberate mislead by him. Sure, creation magic and primal summoning follow the same principle on paper, but in practice it's like comparing a masterfully crafted piece of artisanship with some cheap bootleg that only barely resembles the original and will set itself on fire if looked at the wrong way. Also if mommy and daddy crystal were primals, then logically ALL of the countless plants and animals originating from creation magic would have to be primals as well, no?
(As for the ascians getting tempered, this might've simply been an unintended side effect of Zodiark stopping the terminus. After all, a big part was the chain reaction of the mass hysteria amongst the ancients creating more monsters, so Zodiark might've simply decided that ASSUMING DIRECT CONTROL via tempering as a way to stop that)