What happened to the DW-12?

Evidently IndyCar has dropped the Dan Wheldon chassis designation. According to this official box score, it has been renamed: "All Cars use fourth-generation Verizon IndyCar Series Chassis (IR-12) and Firestone Tires"

We'd love to know the back-story on this. Why? The series made such a big deal about naming the chassis after Dan. Now they quietly rename it otherwise. Why now do they not want to be associated with him? A memorial with an expiration date? How greasy. Meanwhile Dan is still dead….. Steve Heckard