I mean, compare them to whats required to upgrade Artifact and Relic armor...they required delve items and VW items to upgrade...they didn't require anything from Dynamis
Technically they did require items from Dynamis - crafting items, such as Sparkling Stones, Wootz Ore etc for the 109 upgrade.
If anything, it'll be the same way for Abyssea. You'll still need delve boss items and chapters for upgrades, but you'll also need two crafting materials, one of which will be abyssea-specific.
For all we know it could be as simple as NM pop items, like Snow God Cores, Darkflame Arms etc.