Neither is Iowa State-Kansas.
KU is an absolute blueblood, with four Final Fours and a national title since the last time we made the Elite Eight, and Self is 8-2 against Hoiberg, or 7-2 if you don't count the screwjob in '13.
It could be a rivalry but it definitely isn't at the moment. ISU needs to beat KU more consistently and win the Big 12 at least once (compared to KU's 10 in a row) in order to even start using the word as a "maybe."
It most definitely is, and has been for a very long time. Sure KU owns the series, but that is the case with every school. My first ISU game was on 1996 when Kansas came to Hilton. It was very apparent in 96 that this was a rivalry.