Chris is right.
MS is trying to turn Xbox Game Pass into the "Netflix of gaming". New Netflix Original content gets released every month these days, I think? The days of Netflix having a reputation of producing nothing but quality is over, South Park: The Fractured But Whole joking that they greenlight everything rubs that in. Crackdown 3 is a "filler" game out to avoid new exclusive content droughts between the mega AAA blockbusters like Halo, Gears; i.e. the equivalent the Netfix's mega shows like Daredevil and Altered Carbon. Crackdown 3 sits perfectly with MS acquisition of B-tier developers like Undead Labs, Compulsion Games.
Also the fact that if MS cancelled Crackdown 3 it'd sully their already tarnished reputation of lacking first party games. They cancelled several high profile first party games in a row:- Scalebound, Phantom Dust proper remake, Fable Legends. Crackdown 3 was delayed many times and has gone through at least five different studios, I think at this point they're just going to push it out to save face.