Paladins can still heal stacked targets exceptionally well. Shamans, after 5.0, seem to be doing great. Monks are doing well at stacked healing too. Thus, they will shine on Feng.
Spread healing favors druids. Monks are going to do well at this too. Priests have a lot more in their toolbelt than many other classes for AOE healing while spread.
Overall though I might agree - priest probably needs a minor boost of some sort. I'm just not sure Feng is the best example you should use.