Who needs anything other than warlock, just a team of warlocks trying to deal with their contracts and differing interests of their patrons. You got power, drama, plot, and character!
But more seriously, I want to them to introduce all the classes and the full origin cast before moving on to expanding the act. The mechanics and how they interact need to be settled before more quests can be implemented with those mechanics in mind. I'd say the same for non origin companions, something I have requested a lot, and other things many people have requested. The base of a house needs to be built before the walls or the roof. That being said, I think some parts of the base do need to be adjusted closer to 5e so it can be stronger and more stable as a base.
