Not really. If the heroic weapon gives you more than the 9% PvP-power in damage, then it is worth using even in PvP.
And at 32 ilvls disparity, it is highly likely that the HC Starshatter does more than 9% damage on non-PvP targets. At which point the PvP-power wont allow such low ilvl weapon to catch up on damage output (on PvP-targets).