I think the general term should be multi-actor. I understand why people use the term multiplayer, I think: familiarity. But players imply play which implies games, so it's not a great fit outside of them.

The type of thing you're talking about with Warcraft is a deterministic simulation. As long as you have deterministic simulation, and you synchronize your inputs by buffering sufficiently for the input latency of all the remote participants, that ensures everything stays 1:1 between each local simulation.