You are just assuming what they would do with experience balancing - not considering that the later we went with expansions, the easier it got leveling up. Remember when in 2.0 you leveled through FATES (which before StB gave laughable EXP) and spamming dungeons? I do. Since then, they gave us more and more tools for getting tomes and EXP, so it's a rather safe approach to assume that it is NOT in their interest slowing down the leveling process. And people would definitely get upset with the MSQ boosted EXP being just gone, so I really wouldn't put it past them in just redistributing it. Some actually give really low rewards as things are.