The decision to remove The Last of Us Part 2's Faction multiplayer mode was apparently made because it was too ambitious. Naughty Dog confirmed yesterday that The Last of Us Part 2 won't have multiplayer, despite its popularity in the first game.
Multiplayer in The Last of Us took the form of Factions mode, which took several survival and stealth elements of the game's single-player campaign and applied it to player-versus-player combat. Given the emphasis Naughty Dog on The Last of Us' widely-praised single-player campaign, the Factions mode was surprisingly popular. While it's no longer playable on PS3, the original game's Factions mode can still be experienced in The Last of Us Remastered, on PS Plus in October.
After Naughty Dog confirmed Factions wouldn't be returning for The Last of Us Part 2, the news gathered a considerable amount of media and fan attention. In response, Naughty Dog released a statement on its official Twitter account. Faction's wasn't scrapped because of competition from other, entirely multiplayer-focused games, as some assumed was the case. While the mode was indeed cut because of a desire to focus solely on The Last of Us Part 2's single-player story, this only happened because the team's vision for the mode was apparently too ambitious. The studio began developing the next step for factions mode, but it shifted into something larger than an additional mode that could be included with The Last of Us Part 2's "enormous" single-player campaign (so enormous that it reportedly comes on two discs).
An update regarding multiplayer: pic.twitter.com/CUd98LgJGC— Naughty Dog (@Naughty_Dog) September 27, 2019
Naughty Dog's statement seems to imply that, while the team's focus has been on single-player, at least some form of multiplayer development could be taking place alongside it. It could end up being a sort of standalone expansion along the lines of Rockstar's multiplayer titles, like Red Dead Online. The Last of Us Part 2 took quite a long time to develop, so it could be a while before Naughty Dog is ready to show its multiplayer mode - although, if it's anything like the original game's multiplayer, the single-player mode's mechanics have likely already provided a basis for Factions.
Naughty Dog released a The Last of Us Part 2 demo breakdown yesterday that explains some of the game's finer elements, and there's quite a few new mechanics in single-player. Ellie is more agile than Joel (who is now confirmed to return in the Last of Us Part 2), which will be useful when she has to avoid the new scent-tracking dog enemies. It could be interesting to see how these new mechanics would play into a The Last of Us Part 2 multiplayer mode, and it sounds like Naughty Dog is planning to deliver that, eventually.
Source: Naughty Dog/Twitter