Iaijutsu: Horizontal Blade is currently a requirement for Kakita Duelist Rank 2. (Formerly, Crescent Moon Style was.) Horizontal Blade and Crescent Moon are both Rank 2 kata.

Is this an error, or can characters access kata above their current Rank if it's a requirement of their School advancement table?

19 minutes ago, Doji Meshou said:

Iaijutsu: Horizontal Blade is currently a requirement for Kakita Duelist Rank 2. (Formerly, Crescent Moon Style was.) Horizontal Blade and Crescent Moon are both Rank 2 kata.

Is this an error, or can characters access kata above their current Rank if it's a requirement of their School advancement table?

It's not actually required, but yes, per the instructions, if it's on the school list, you don't need to meet the prerequisites to buy it.

Page 107: Note that if a character receives a technique during character creation (or at another time) for which they do not meet the prerequisites, they can still use this technique—prerequisites apply only to the option to learn the technique by spending experience.

Page 44: In addition to the listed general restrictions in Table 2–2: Advancement Costs, some individual advancements have prerequisites. To purchase an advancement, a character must meet all of its prerequisites or the advancement must be listed in the character’s current school rank.

Note the "or" on page 44.

For my part, Are the two Iaijutsu cut techniques actually supposed to be 2-point techniques, instead of 3 like all the other "gives a special action" techniques?

Good spot on page 44: thanks!

I should also point out: no single item in the given ranks is required, AFAICT. You just have to get enough of them overall. And neither Iai tech is prerequisite for the other.