Does the community have a custom version of Rage? Or is this a LW bug?
Yes. A Special was made for bootstrapping since almost all instances of Rage have the same scripting. This way things like PrC's that check for Rage don't have to go through the entire lineup of checks and feats like Extra Rage only have to worry about the one ability.
Kinda like how Turn / Rebuke Undead is it's own special.