Classically there was no level req for the AoE for Painbringer or the Haste for Executioners Axe.
http://web.archive.org/web/200006152...nt/1HSlash.htm
http://web.archive.org/web/200006191...nt/2HSlash.htm
You can see other weapons have the level requirement (such as Ebony Bladed Sword: Damage 7, Delay 24, Weight 2. Effect of Ensnaring Roots (after level 25) and Gnoll Hide Lariat: Damage 3, Delay 20, AC 3. Effect of Stun [at level 25]).
Will see if i can find patch notes.