One of Diablo 4‘s upcoming features, which is anticipated by many in the core community, will not be in the game soon as initially planned. Before the launch of Season of the Construct, Blizzard talked about implementing leaderboards, which will be tied to the new Gauntlet endgame dungeon.
The plan was for Season of the Construct to launch, give everyone time to explore the new mechanics and content, then launch the Gauntlet. In other words, it was expected to arrive fairly shortly after Season 3 kicked off.