CU and WVU stayed in the same tier of BCS or P5 status. More of a lateral move.
Utah and TCU at the time were busting the BCS and beating national powerhouse schools on NY bowls while winning out in the best non-BCS conference. They were ready. BYU fans are probably the only people in the country that would say Utah and TCU weren't ready or have been a disappointment.
BYU, similar to Boise, was very dominant in the weaker WAC. Once BYU got to the more challenging MWC, they were great... but not elite.
I've heard BYU fans say they were better in the MW...I don't get that. Utah had more wins, more notoriety...by the end, BYU couldn't even stay on the field against TCU.
I'd argue neither BYU or Boise accomplished much on the national level in the MWC.
But to your Cincy and UCF argument, Cincy was already BCS. As soon as a conference needed expansion, when the media deals were coming due...both of those were invited. Once again proving the meritocracy argument...what helped is by now, the AAC has become the top G5 program.
Utah doesn't get invited to the Pac-10 without both BCS bowls. They were lucky to get in for sure...but they needed to leverage every accomplishment imaginable.