Warner will probably be the #1 going forward. Millen the back up if he is even healthy. Hasn't played a regular season game since the opener in 2023 for Colorado St Kessler, Wright and Williams are all walking ons that have never played college ball.
I'm not sure how you prepare Warner this late in the season going into a 3 game stretch that will break all 3rd string QBs. If he can't be relied on passing, then you have to switch to an I formation with a lead FB. At least eat clock and maybe with the change, defenses aren't prepared to stop it.
There is not any news I can find. He did have a shoulder injury at CSU that lost him the QB job there. Maybe he never fully recovered from it.