I have read about “welcome to the arc” but is still unclear what it is to me. "Experience the exciting first battles between the UNSC and The Banished. Unlocks the story missions and multiplayer leaders from the original Halo Wars 2 campaign. The original halo wars 2 campaign doesn’t make sense. Do they mean from the first halo wars? That is the description from
https://store.xbox.com/en-US/Xbox-One/DLC/Welcome-to-the-Ark/aa9e6c3f-699c-4a3d-8401-7be483dc8fc1
This baffles me too. Anyone have any ideas?
Halo wars two takes place on installation 00 aka the ark. It is set in 2559, post halo 5.