The developers of the game Diablo 4 spoke about the role partners will play in the project.
The authors noted that on the release, players should not count on the fact that NPCs will often accompany them. Yes, at some point, NPCs will fight demons in your company, but this will happen in strictly limited time intervals. In a word, such extensive interaction, as in Diablo 2, should not be expected from them.
Meanwhile, Blizzard notes that this may change in the future. When exactly is not known.
Recall that the release of Diablo 4 will take place on June 6, 2023.