I'm thinking of Warhammer as being the model for this game, too. The Capital cycle was the fourth battle pack cycle, so I suppose it'll be a while before SW LCG gets anything similar, but I doubt we'll see Force packs that only have one or two factions' objective sets. It would make sense to have one for each so they sell to the maximum number of people, after all. So I'm assuming one objective set for each expansion, with four of them doubled up in some rota-fashion maybe. I'm also assuming the deluxe expansion will still provide cards for the four core factions, much as Assault on Ulthuan provided cards for the core races of Warhammer.
Unfortunately, having only one objective set for your faction of choice within each Force pack, whether you get two copies of it or one, is going to make the game grow very slowly…
If I'm primarily a Sith player (which I may just be) and I have to go a month with no cards for my favorite faction, I am less likely to purchase the product. If I am primarily a Smugglers and Spies player, I'm living 8 months in the future, so it doesn't matter yet. But what happens when it does matter?
The thing though is that even if you're a Sith player you need to have a light side preference as well. The way they can get away with neutrals while "neglecting some factions is alternating force paces that have all three factions of LS + neutrals + 1 faction of DS, then flip it next month. Could that make the meta for one side stronger, sure but only for a month and since players are playing both sides they both have that advantage.