There may be an error in the article, the DROID RAZR (Verizon) is listed on their site as running JB 4.1.2 along with DROID RAZR MAXX (Verizon). It, along with the Bionic, are based on TI OMAP SOCs.
It seems that any device that launched with a TI OMAP SOC is no longer being supported. This is very likely to be because TI exited the SOC market and thus no official driver is currently being developed/validated for anything beyond Android 4.1.2. I doubt Google/Motorola is going to accept the liability of taking over driver development for TI.
Note: the PHOTON Q 4G (Sprint) is listed as "Future plan coming soon" there may be hope for that phone after all