This board is designed specifically for the LaunchPad series of development platforms. We thought it was the best way to go because of the availability of the MSP430 LaunchPad.
As far as I know, you can't develop code with Energia for the EZ430-RF2500.
Also, because of the wide variety of wireless solutions, we wanted to keep that open (for now). We ran into a situation where the 2.4GHz radio would not work in the environment we needed it to. So we had to go and find another solution. This leaves it open for the user.