The Anti-SOS have the makings of recurring villains. Perhaps what happens in Vol. 10 forces them to stick together... or maybe they all just transfer into Sasaki's school.
Man that would rather suck for her, huh?
Although I think what they need to continue to be important is their own Kyon to narrate stories about them. That would be awesome.
...There ARE two Kyons in Vol. 9/10...