I think it will be fascinating if Halo 6 comes out this year. No main halo game has been announce and released in the same year that I can find.
There is usually a year difference between the E3 announcement, and the game releasing. With halo 5 being a two year break. So Halo 6 being announced AND releasing in the same year would be quite different.
That is only a 5 month turn around. There is very little time to hype up the game.
I think we're seeing a shift to shorter reveal-to-release times in the industry. Bethesda has already committed to 5-month cycle, and Nintendo is doing it too (at least for its B-tier and third party games)
I feel like the 5 month cycle will actually produce more hype than normal, like fallout 4
Bet with Intrinsic:
The Switch will outsell 3DS (based on VGchartz numbers), according to me, while Intrinsic thinks the opposite will hold true. One month avatar control for the loser's avatar.