Older Motorola devices not supported by Bootloader Unlock tool
Droid Life

In a tweet posted to Motorola's official Twitter account, it has been revealed that support for older devices in its recently launched bootloader unlock tool is "not currently in the plan." Apparently, only more recent devices can be used with Motorola's Unlock My Device web site, and these ar ethe Motorola Photon Q, Motorola XOOM, and the European version of the RAZR Developer Edition. This is surely bad news for owners of older Motorola devices, but perhaps there may still be a chance that support will be added in the future.

What Else You Need To Know:

- Some older devices that cannot be used with the unlock tool include the Motorola Droid Bionic, Droid 3, or Droid X2.

Other sources

We’ve seen a public outcry for these things in the past cause HTC to cave on decisions, but I have a feeling we won’t be so lucky with Motorola. - Cory Gunther, Android Community  
Droid Life
Moto Unlock Tool Not Coming to Older Devices Like the Bionic or DROID 3
Android Community
Motorola has no plans to unlock older devices  

Motorola has just released an informal statement over on Twitter regarding the bootloader unlock process they’ve recently released.

Motorola says bringing device unlock tool for older devices “not currently in the plan”
Motorola Screws Droid Bionic Owners Again  

The Droid Bionic bootloader isn’t in line for an unlock.

Android Police
Motorola Confirms Via Twitter That Older Devices Will Not Receive Bootloader Unlock Tools  

Moto has no plans to add any of its older lineup to the supported list.

Motorola Not Planning To Release An Unlock Tool For Older Devices  

Bad news for owners of an older Motorola device today as Motorola reported via their official Twitter account today that a bootloader unlock tool would not be available for older devices such as the DROID Bionic and DROID 3.

Phone Arena
Tweet from Motorola says unlocking older models "not currently in the plan"
Motorola: Bootloader unlock tool for previous devices not currently in the plan
Geeky Gadgets
Motorola has no plans to add bootloader unlocking support to older devices
Motorola says no bootloader unlocking for older devices