From: http://www.wowhead.com/news=253854/t...stem-in-legion
Max Level Dungeons: 805 Normal, 825 Heroic, 840 Mythic
Raids: 835 LFR, 850 Normal, 865 Heroic, 880 Mythic
Crafted: 815, upgraded to 850 via Obliterum
World Quests: 805, reward increases based on ilvl of your current gear.
Hellfire Citadel loot is also affected by this item system in the 7.0 prepatch.
Some additional loot that is not part of this system, as it has no + as part of the tooltip:
World Bosses: 860
Legendaries: 895
Order Hall Set: 810 upgraded to 840 via tokens
In WoD you could at least build three BiS Heroic items. Now the only ones who want to craft could be LFR raiders, but those people usually don't have the time for crafting (farming materials). Why do they make crafting completely irrelevant for raiders again? Even in Burning Crusade there where at least some raid drop receipts that gave bis items and a single very good item outside of raids to craft.
Right now all you need to do is world quests, heroic dungeons and order hall stuff and you have a set good enough for normal mode raiding. Then you switch to heroic and after that mythic. Once you reach heroic raiding nearly all content becomes obsolete since it doesn't offer an upgrade.