That's because of us. Grifball's always been a community-created playlist. If the Grifball playlist were available at launch, it would have had one gametype and one map. 343's first big playlist expansion came in early 2013, which is when the Grifball community was ready with improved settings and several community-created maps.

There's no other gametype like it. Like I said, 343's close work with the Grifball community has really impressed me.

: That sounds backwards to me. Either way I wouldn't want to have to change
: Grifball around just to get Assault (although I'd like it better than what
: we have), but then it would probably have its own gametype slot or show up
: somewhat differently. What about one-sided Assault and regular two-bomb
: Assault?

Looks like something that was half-implimented. Hope they can finish it in Halo 5.