Yeah, should this be legit, it isn't USC or Texas moving, but its still a major deal. Its passing the instability hat to the Pac 12, who now will have lost three members in a year with little to no options to stop the bleeding. They could have stuck together at ten, but at nine, they can't.
Colorado doesn't have the brand value of Texas, but it has a brand value and that is leaps and bounds ahead of any G5 school. So not only did the B12 pick up a geographically attached Power Five school, it destabilized the Pac12 even more.
The probability of other Pac schools now reaching out to the B12 are much, much greater than they were last week. And while nailing down an Oregon/Washington would possibly even add more value, just grabbing Arizona adds more brand cache to the conference.
The Pac, on the other hand, is painted into a corner, literally. There are no P5 schools available to them to expand with. SDSU or SMU don't bring same value, let alone increasing it. So of the 9 who are left, how confident are you on your future? Its a bad place to be.