So on Gear Progression in Dragonflight.
Seems that the raid doesn't have a set ilvl for most bosses. Rather there is a large range of ilvls from the first to the final boss. E.g. Mythic Eranog is 424, Mythic Terros (the next one) is 427, Mythic Dathea is 431 and Diurna is 434. I have no idea how that is supposed to make sense. It effectively makes earlier bosses irrelevant faster. And this is a small raid to being with.
As for professions, there seems to be a bit of timegating with Spark of Ingenuity coming from the Tyrhold area from a quest (that seems to not be repeatable so weekly? Daily?)
My question is where does Primal Chaos drop? Does it drop just in instances or also from Elites in Elite areas or from World Quests? If you are up for a lot of grinding, primal chaos gives you Primal Infusion which is used to craft mid Heroic Ilvl gear (414 so the ilvl of the 2nd-4th Vault bosses). Given people can exchange Primal Chaos to buy potions from the new cauldrons, I somehow doubt it will be a very limited resource.