Blizzard has changed the quality of items dropping from Mythic +0 dungeons and Raid Finder difficulty on the Dragonflight Beta.

As of the most recent build, regular Mythic dungeons drops Rare (blue) gear instead of Epic (purple).

The first four bosses in the Vault of the Incarnates raid also drop blue gear on Raid Finder difficulty. Vault has 3 item level tiers (up from 2) and the later bosses drop better gear.