The guidelines of qualification allow for PRO players who are not recognized as "touring" pros. The touring pros are listed on the PDGA website. So you can have former cash winners on your team and many of the teams do (including Kansas).
I think it's important to recognize that this is not a sanctioned NCAA event, nor is it considered a "Varsity" sport at any of the participating college, it's a "club" event therefore the guidelines are much more relaxed than say football, baseball, or basketball. The disc golf teams are actually "clubs" at their schools and are given permission to represent their school at this event (sorta like quiz bowl or marching band).