The shaman class preview also has no spells listed as stronger than moderate - but every other healer has an abundance of high throughput options. The description of Wild Growth is really telling. Our only true AoE heal already has a 10 second CD (when every other healing spec except Paladin has a spammable AoE), and is already limited by being a HOT. retains the same high mana cost it has on live (more overhealing) and also has a cast time, and isn't a true smart heal (like Renewing Mist/Chain Heal). Given all of those limitations, how is WG considered only a "moderate" power heal? It should be significantly stronger. The strength of WG on live (plus the power of Tranq) is the only thing propping the Resto Druid spec up this expansion. Rejuv already hits like a wet noodle. Drop WG to a moderate AoE heal instead of the HPM/HPS monster that it currently is and spec is Holy Priest level.
The other alarming thing that this suggests in terms of balance is that they are going to have to buff the living bejesus out of Tranq to make Druid numbers look in line with other healers. That's something that I already feared would happen with their refusal to allow a mechanic for Tranq while moving. Realistically, to justify Tranq having a channel time, plus the need to remain stationary for 8 seconds, the healing that it does should blow stuff like HTT and Revival out of the water. It clearly doesn't on live, but I could see them being justified in tuning it that way for Legion to emphasize the value of the niche/mechanics differences. Of course, that's a horrible idea, because would you really want to be tuned around something like 40% of your output coming from a 3 minute CD that can be fairly limited in its use for some mechanics and on some fights? There's a very real danger that they are headed in that direction or will be forced to tune in that direction to compensate for the mediocrity of the rest of our kit.