"Essentially the Scrap-o-Matic 1000 works like the Obliterum Forge in Legion however one major difference from Legion is that you can use it to break down any gear obtained that is from the Battle for Azeroth expansion, including dungeon/raid drops, quest rewards, world drops and crafted gear. Apart from a chance at getting Expulsom you will also get ore, gems, leather, occasional enchanting mats (from scrapping cloth gear) and other crafting mats. The best way to obtain Expulsom seems to be from breaking down rare/epic gear you obtain from dungeons and raids, killing rare elites and doing world quests, it also drops rarely from BFA uncommon quality items."
In Legion, some of the dungeons include the Black Rook Hold, a max-level dungeon in Val’Sharah that once served as an elven fortress but has been corrupted by a malevolent force. If you decide to quest in Stormheim, you can also try to clear the Halls of Valor, which lets you take on the Vrykul God-King and vanquish the pure Val’kyr that are superior to those found in Northrend.
Don't have data from beta and didn't read much into this, so i just speculate based on what i've seen, that there are different champion equipment craftable, each with different bonus. So my guess is that people will use these equipments pretty much similarly as they use glyphs (from a market analogy): equip their champions once and be done with it.