They will never involve DOL and DOH because they are not mandatory to use. There are enough people who just have one character and would moan if they have to level a DOH/DOL just to receive an Endgame weapon. They made DOL interesting with treasure maps but still, ppl rather buy them from the market than levelling their own DOL. So whatever will be the new Grind, it won't be for DOL. IMO.