I used to think halo 5: xxxxxx would be made, but i don't even know anymore. Their sustain is filling in the Halo gaps for me.
If they release a halo 5 : xxxx, i think it would lose any type of appeal or hype compared to a proper sequel like announcing halo 6.
Can't forget Halolens and how that may factor their business decision for Halo Spin-offs in the future. Like a halolens audio book watching characters perform for you in your living room
Oh , better yet have Hunt The Truth as an interactive HaloLens expeirence for free with purchase
. I'm still in awe about the amazing work they did with HTT.
Probably won't be for another 6+ years though.....