Actually, 'jumping to conclusions' is literally something they do in Anabeisos' wrapups, and with even more tenuous subjects.
Frankly, most of what they say about Ultima the High Seraph, and a bunch of what they suppose in relation to Athena in the epilogue that opens if you've done Ivalice, are extremely tenuous given what little evidence they actually have... but are obviously the stuff being put forward to us as true, or at least true enough to chew on. 'Auracite is crystallized dynamis' would actually be less of a leap than the ones they actually make. So the fact that they don't make that leap for us tells me that they don't want us to make that leap.
Overtime I've learned that a big part of how the game doles out lore can be discerned by emphasis. This is not a game that trades in subtlety; if they want you to notice something, they'll spotlight it center-stage, not far from the things you're meant to associate it with, because they want the game to still be understood perfectly well no matter how little someone's paying attention (it's the same reason the game reminds you of someone you've met before if it's been a while or if they're not easily distinguished from their group). If they don't, then they're not doing anything with that, at least not yet.
So with this... no, as much as your idea makes a lot more sense than the average dynamis theory, I'm disinclined to think that we have all the pieces to reach such a conclusion, and they just didn't say anything. If auracite and dynamis are related but the relationship just wasn't mentioned, then it requires an extra third element of that relationship that's so buck-wild that it'd be
more important than the dynamis. (And probably hasn't even been thought of yet by the writers, or again, they'd have hinted.)