I'm assuming it wasn't because of time restrictions, so how come Halo Wars 2's campaign just stops???
I know well Halo games since my childhood to know they will probably leave Halo Wars ending, Atriox angry to take control back, Anders in the ring, Cutter devastated by his lost, Isabel taking control of the Spirit of Fire, Jerome as a new commander, Voridus and Pavium with their crazy little cute pack brothers adventures, and so on for the Halo Wars universe while creating new characters for Halo Infinite. Still 10% probabilities they will mention it, maybe in some log in a lost data memory card deep in some dark area of the world. That is all the link you will see from Halo Wars 2 ending and the next FPS game.
Which I feel it is good to keep both "sagas" have their own characters, tones and plays in the Halo Universe. I just pray everyday (not everyday but every week or month) to get news for Halo Wars. A new expansion, a new dlc, a new something... Give me something 343i and CA!!!! I need my doses of Halo Wars hype methane drug!