343 are hinting that we probably shouldn't be expecting to see the next chapter of Halo's mainline story in 2018, albeit pretty vaguely.
Halo 5 is now getting on a bit and it is beginning to feel like time might be right for the franchise to start turning its head towards the future. There have been some rumbles recently that might lead one to believe the next instalment might be on the horizon, however it seems it might be time to cool that speculaton.
In a blog post on the 343 website, the developer talked about what was coming up in 2018. While it is clear they have a fair bit planned, it seems we can strike Halo 6 from our expectations for the next 12 months. Probably. In a rather vague sentence, the studios seemingly waved off expectations saying not 'those' adventures, which one would assume means the Halo mainline series. It reads:
2018 has arrived and with it, the promise of new fun times to be had and adventures to be embarked upon. No, not those adventures, but plenty of exciting ones regardless – some which might surprise you more than others
Now, the vagueness of the remark leaves this open to a lot of interpretation and I certainly don't think it excludes an announcement for the game in 2018. I believe there is a very strong chance we might see it at E3 this year. That said, this is in line with the studio insisting the game is a ways off not too long ago. However, it is also worth noting that they do hint at other adventures. Is it possible we might be looking at a game in between mainline games? An ODST or Reach for the current-gen console? Not impossible. Hopefully, in time the situation will present itself.