Metropolitan State University - Online Programs

Metropolitan State University seems to have removed non-resident fees and everyone in state/out of state are getting the same tuition. However, having said that, does anyone know why their courses are 4 credits vs 3 credits? They have some interesting online degrees at the Masters level for about 18K though...

Online programs: Online Degree Programs | Online Bachelor's and Master's | Metropolitan State University (metrostate.edu)
Tuition changed for Fall 2021: An affordable, quality education | Metropolitan State University (metrostate.edu)