The sky is falling! I really don't want to be this person. The issue is that we, as hunters, have been on the low side in expansions before. Blizzard eventually fixed us with various buffs here and there but those always happened after months of progressive raiding occurred.
The sky is falling! Our numbers are low. They're like really low. Like holy priests can out-dps hunters. All three specs are terrible. We're half the damage done in simulators of warriors and mages and far far behind everyone else.
The sky is falling! There are tons of caveats with the sims. The most commonly circulated ones are "Patchwerk" style. Hunters are supposed to be the dps-on-the-move class. So, in a "Helter-Skelter" simcraft set-up, we should be much better. Well, no. We should be as close to the same as possible and everyone else should be worse. 50% worse? That's hard to believe, right?
The sky is falling! Are the sims right? Nope! Many sims are looking at level 90 and frankly, Blizzard doesn't care about balancing anything at level 90 anymore. Are the sims doing the right conservation of focus for the shots, or prioritizing correctly? I somewhat doubt it. The simcrafters are trying to model dozens of specializations. Even if just looking at hunters, you need to pick some heuristics and tweak focus regen and stat weights (gems, enchants, etc) around it.
The sky is falling! But Survival just got a buff and others got buffs and nerfs. That's great, but it isn't great in that it was enough of a buff/nerf. It's great that Blizzard is tweaking as well.
The sky is falling! Here's the thing the simulators have an easier time and a harder time. It's easier because there are less stat weighting to consider. It's easier because there are less abilities to prioritize. It's harder because there hasn't been enough thought and experimentation by creative people into what should be done. All that said, on the surface and at first cut, hunters are in the dps basement.
The sky is falling! For now, just enjoy your time. Try the new UBRS. Get your stuff in order. Prepare to level. Try out MM, BM, and SV. Try and get some muscle memory going with rotations. Get your addons so you can more easily visualize what you need to watch. Try raiding if you raid. If Blizzard is watching they'll see the numbers and continue to tweak.