they were 200% planning to make a barrens warfront bro why do you think they spent so much time upgrading quillboar assets for bfa. i'll give you a hint not because kul tiras is known for having shit tons of quillboar for no reason.

there was going to be a warfront per tier. heroic warfronts only came about when they scrapped the concept.

darkshore was either supposed to be warfront 3 or 4 but they brought it forward to be #2 because of its story importance to shadowlands. you can tell this is true by how the timeline makes no sense when its simultaneous with dazar'alor, nathanos is simultaneously leading both fights and genn promises to help darkshore but then goes to dazar'alor anyway. this is also why the warfront is only half finished and they never put in more generals than the warden and evil warden.