I sincerely hope that they all do. I know that's kind of nuts in an LCG format, but L5R without Lion, Crane, Scorpion, Crab, Dragon, Unicorn, etc. just wouldn't feel right. We know, because of Warhammer, that it's entirely possible to include 9 "clans" in an LCG. In fact, most of their games seem to have upwards of 7+ factions. But what if they can't? And what if they only release with 6 clans in the start?
So, let's say that they can only include 6 clans at the start of the game. Who makes the cut? Who would you cut out? Could we consolidate multiple clans into one single clan? What if they can't include all 9 in the course of the game's lifetime and one or two don't make it at all?