The only reason I can reason that CSU would be included above the 4 other schools you mentioned would be that Colorado politics are involved. Much like Kansas is tied to KSU, Texas to TT and Oklahoma to OSU.
Substituting CSU for UCONN or Cincy would be a partner for WV should be considered. And BYU is more attractive to providers ($$$) than CSU.
Not sure why Colorado politics would have the interest in this case, as CSU has never been a P5, nor have they been seriously considered for addition to a P5. Basically, they don't have anything to lose if they aren't included.
I also think the politics of these deals has been overblown in message board chatter, and it is all based on UT dragging the other Texas schools along with them when the SWAC fell apart. As we all know, UT plays by a different set of rules.
There were quotes in the KC Star by Kansas regents in the last round of expansion saying that they would like the two state schools to stay together, but they wouldn't force it. I used to have the article bookmarked. Basically, if KU had a home and KSU didn't, they wouldn't let KSU be the anchor to drown them both.
I've never seen anything official about the Oklahoma schools being a package deal, again just internet speculation likely based on the old rumor of the 6 B12 schools going west. OSU doesn't deliver an added media market to the PAC, nor do they meet the academic standards, so I guess there was an assumption there that they were pulled along by OU. This may be true, but seeing as it can't ever be confirmed if that expansion deal was agreed upon by the PAC schools and extended to the 6 candidates, it is again speculation at best.
...Also find it funny that the general consensus on this message board is that all of these state schools and governments will look out for their fellow state schools, but whenever there is discussion about ISU to the B1G, everyone is convinced that UI will do everything possible to keep us out.