Questing XP

Im returning after a year and a bit away. I was formally really hardcore and pushing high level mythic keys. But as ive returned I have returned, ive actually become very casual enjoying the questing and collecting side of wow now (which I personally never thought would happen XD)

Anyway my question comes in as. Would Blizzard ever consider another XP toggle? As it stands now I leveled from 1-70 and ready for TTW by just doing 6 zones in Cataclysm Chromie time. That was extremely fast as well. I know we can turn XP off. But what about another toggle that would say only give like 5-10% XP gains rather then the normal?