Well, it’s just me, but Energy Ball is one of those moves where many Pokemon can learn it. It’s a good move, but it stops when a target crosses the line of sight. It’s one of the few Grass moves that a large amount of Pokemon can all learn from TM, being rivaled by Solar Beam because it hits in a line without stopping. It’s really difficult to train with Solar Beam, since it requires Sun, which you’ll have to make, either with Sunny Day or Drought, and not many Pokemon have Drought. It would also be slightly inasane if you do something like TC with Solar Beam, since you would have to use Sunny Day on a lot of floors. I understand that it’s unlikely for it to be ever changed to a LoS like Solar Beam, but perhaps a bit more PP, since it can’t hit multiple enemies at the same time?
Energy Ball, Shadow Ball and Aura Sphere are examples of single-target moves. I don’t think it will change from a single-target move simply because it’s a pretty balanced move. Besides, if it was to change, people would want moves that they use to be changed from single-target too.
Well, I understand it probably will never be changed to a multiple target LoS… It’s animation is a ball made out of nature’s energy, so it would naturally burst after hitting something, but a PP increase would suffice, since it takes more hits to take out enemies since you have to kill them individually.