: I also liked that we got to see the tension between the colonies and the UNSC
: in game, and I can see that becoming more and more relevant as the series
: continues (although I don't think we'll see a Insurrectionist war in the
: games; I feel like they'll steer away from shooting other humans in Halo).

I think we lost our opportunity to add human enemies with Reach. That could have been a prime opportunity to introduce some hostile Innie enemies, at the start, during the first mission. Make it that the relay WAS down due to Insurrectionist activity, but that it was ALSO being taken advantage of by the Covenant. Then, later, during New Alexandria those same Innies turn up again, this time pinned down by Covenant fire and willing to help out the UNSC if it means saving their families. Show people uniting against the enemy, however reluctantly.

Or I guess, given recent EU happenings, you could introduce Insurrectionist Spartan defectors, with similar behavioural AI as Elites or Promethean Soldiers. Or, if Halo 5 had actually made ONI the bad guys as a lot of people thought, pit the Chief and Locke against ONI's own secret cadre of MJOLNIR-equipped badasses.

As it is, I can't see how you can continue the Insurrection now. The enemy of my enemy is my friend, and even an overbearing centralised Earth government has to be more appealing to the Outer Colonist veterans than an omnipotent AI dictatorship, no matter how benevolent it proclaims itself to be. And it would be great to see that happening - Infinity joining up with the folks out on Venezia or somewhere to take back human space from Cortana. Going colony by colony, uniting the colonies as never before, against a foe that makes even the Covenant look downright tame by comparison.