I don't know the current status of the quest due to the patch yesterday. Supposedly, it was fixed and opened up to non-heroic characters. Regardless if it's still bugged or not, I'm sure it will be a priority to get fixed since the Heroic Character Upgrades are a pricey RMT item.

With that said, it was implemented specifically for Heroic Characters which come equipped with 4kish AA, VoA T1 Gear (I think). You're level is right on par, but only you could judge how developed your Characters are in relation to the Heroic Characters.

You can always try it and risk wiping to see what happens