What Blizzard has actually said about Diablo V multiplayer

Asked about multiplayer after the reveal, the team said the game can be played solo or in a group, and that they will have more to share as development goes on.

That is the complete public record. It is worth saying plainly, because the gap between "multiplayer exists" and "we know how multiplayer works" is where a great deal of confident writing is about to happen.

What has not been said

• Whether there is a shared world, and of what size.
• Party size.
• Whether progress carries between solo and group play.
• Crossplay and cross-progression.
• Whether a permanent connection is required.
• Any PvP system at all.

Every one of those is filed as not confirmed on rumors and open questions, and none of them has been answered by implication either - a caravan of survivors says nothing about whether somebody else can walk through it.

Why this is a developer statement, not confirmed

It was said in an interview, not published by Blizzard. Our trust states keep those apart on purpose: an answer given on the spot is a real signal, but it is not the same thing as a sentence Blizzard has committed to print.