The idea of an infinite dungeon is something players have asked for before. I adore them. I put far too much time in Dungeon Hack and the Neverwinter Nights: Infinite Dungeons module. I asked Wilson why this was coming as a Challenge League expansion instead of a permanent offering, and he said Grinding Gear worried players would enjoy a never-ending delve so much that they never come out and play the story portion of the game.