It's no great surprise that the new factions aren't included in these work orders, to be able to earn reputation for the new factions by farming would be rather strange when they have only just appeared. There doesn't, at present, appear to be any prior reputation requirement to get these work order quests, but you do have to have bought your farm in order to receive the work orders, so a considerable dose of Tillers work is required.
Edit: A blue post has clarified that you no longer have to buy the farm to receive and complete work orders, but you will need to be exalted with the Tillers and have all plots unlocked.
The general consensus seems to be that any way to gain reputation is a bonus, but these don't seem particularly fast. Do they strike a good balance?
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