Certified Asterisk in FreePBX Distro

FreePBX Distro support diferent flavors of asterisk:

Asterisk 1.8
Asterisk 11
Asterisk 13

Actually there is Certified versions of Asterisk 1.8, 11 and recently 13.
Why FreePBX distro don’t support this Certified versions?

From asterisk page: "Certified Asterisk releases have undergone additional testing and are made less frequently - typically two to four times a year. Certified Asterisk releases are generally identical to the Long Term Support release they are based on, save for additional bug fixes that were applied during testing. "

Certified asterisk are also robust versions with less regression bugs and Production Ready.