I don't think this is necessary. There is lots of XP out there for levelling (the explorer areas make a huge difference in available XP).

The only way I could see this being viable is if they did a review on the XP of all quests to make sure they are more balanced. Drop the XP in quests like Stormcleave which are way too easy for the XP they give. Raise up others that are too low. (In other words make a good effort on making quests equally attractive from an XP vantage). The final result should probably be a generally overall lower XP for all quests since the available XP is going up with the repetition reduction getting removed.