I have been out of the loop since right before the release of Children of the Empire. However, I just checked various databases for which sets I need to buy to have a complete collection of the imperials and well...
There seems to have been all of one unaligned imperial card printed since the Children of the Empire set. There have been more Mantis Clan cards printed than Imperial Family cards since then.
WTF did I miss? It seemed like the story was going into a fight between Satoru and Daigatsu, but there has been two cycles and "Children of the Empire" seems to have been a send-off for the entire Imperial Families. We never even got a proper Otomo family character card outside of the borderline unplayable and unnamed one in the core set. That's my favorite family and... not even just one?
I can only suppose they have been deposed by the Scorpion Clan. If so-- and since apparently there is no "Toturi's Army" made up of former Imperials and ronin, is there a chance the various former Imperials scattered across the empire can coalesce into a minor clan some day?