A developer interview discusses the classic Terran, Zerg, and Protoss dynamic. Blizzard has not announced a full faction roster or each group’s role in the new game.
Dan Hay told Inven Global that the Protoss are one of the factions featured. He also pointed to a Protoss structure in the reveal video.
This is an attributed interview statement; the new game's specific Protoss characters, units, or missions have not been detailed.
The interview describes Zerg in the reveal sequence and says the team is considering the asymmetry among the traditional groups.
Specific enemy behaviors, playable status, missions, or combat systems are not confirmed by this description.
The interview describes a recruit in the reveal and talks about the Terran, Zerg, and Protoss dynamic. The reveal presentation also uses Dominion recruitment language.
The new player's exact faction or chain of command has not been announced.
The faction discussion above comes from a direct developer interview, not Blizzard's short official announcement. Legacy canon establishes these groups in the wider StarCraft universe; it does not automatically establish their specific new-game roles.