After an entire season that spanned over the course of just days, the Litchfield riot could end in a countless number of ways. Negotiation attempts aren't leading to a resolution, so the SWAT team storms the prison to force one. Prisoners are dragged out and lined up on the front grass area one by one. Meanwhile, others band with their friends to support one another through an aggressive denouement. They're put on buses to separate prisons and it makes sense why we don't see all of them in season six.
What makes this episode even more pivotal is not just that the prisoner takeover is finally coming to a close, but CO Desi Piscatella is killed by a fellow officer. An accidental one shot to the head was what it took to take down an abusive, power hungry CO.