A 9th Star BB test had a master covering significant amounts of groundwork using a real katana it was very impressive. So I don't know if only some forms don't have kata with groundgame but that's not to say they all don't.
What kind of groundwork requires a katana?
"In case you ever wondered what it's like to be knocked out, it's like waking up from a nightmare only to discover it wasn't a dream." -Forrest Griffin