I've heard several different things: An accredited bachelors program is pretty rare in the planning world... making it an all-masters CRP department might strengthen the profile of the program... would enable a "leaner and meaner" faculty body... I think one of the biggest reasons is that the CAED must comply with a few million in budget cuts and the way to do this is to reduce faculty, but you can't maintain a quality program with bigger and bigger class sizes. They've already cut the size of the entering BS cohort by something like two-thirds, so it's also suddenly become a more elite program.
I think it's a good idea academically. Undergrad students should go after a broader degree and not get so specialized so fast. Also, planning is better suited for a masters degree, since there are many themes that demand a more mature understanding of things than the typical 19- or 20-year-old can bring to the table. They have historically tried to cram too many students through too fast, in my opinion. So if they "slow down" the program, get more selective, make it an all-masters department, expand the masters cohort (previously the undergrad cohort out numbered the masters by like 3 or 4-to-1), it should bring more prestige to the program itself with stronger alumni ties and links to the professional world. There is a much higher percentage of MSCRPs who go into relevant professional paths than BSCRPs. I think that factor will increase, since the demand for planners has dropped so dramatically.