I think the best way to describe the change is a buff that doesn't benefit disc as much as it would direct healers. It's not a nerf (it doesn't reduce their effectiveness at all), but it's just not as exciting for disc as holy or other healing specs.
We'll see if they do a separate buff for disc to compensate it later, but that's kinda iffy since they're trying to avoid bubble spamming again. They might do something, just don't get discouraged.