Why Guardians?

Why is H5 called “Halo 5: Guardians” instead of just Halo 5?
Do you think it has to do with 343 turning the “Reclaimer Trilogy” into the “Reclaimer Saga?”
ie. There will be a Halo 7+ to tie up the reclaimer saga

Maybe there is something in the graphic novels or books that I missed? :smiley: