Its the law of large numbers. In games that cover as much back story and deal with as many characters as FfH and WoW there is always going to be some elements that seem surprisingly similar. Its not influence from one to the other as much as just sharing a genre.
There are influences of course, but they often aren't as direct as people suspect. For example my biggest for the D&D campaigns was a series of novels by Margret Weis and Tracy Hickman called the Death Gate cycle. In their novels the world was broken into multiple worlds based on the elements, so there was an air world, a water world, etc. The books had footnotes at the bottom of the pages with little details about the worlds or culture of the people they were discussing. For me it was a guide to world building as the physical and social elements of the world interacted in a really cool way.
I never used the specific idea, but that did excite me to create a world where the physical and social elements were laid out based on the 21 elements of the mana chart. there were some things borrowed more directly from that series. The main character used rune magic, and Tebryn was very similar to him in his player character life. And the story revolved around a people that escaped the torments of the labyrinth, which was where the story of the Bannor escaping from hell came from. There was even a leader that went back into the labyrinth to rescue more people who became the model for Sabathiel.
Its the themes that are most likely to be shared. As with the Bannor story I loved the thought of a people escaping from this hostile world that tested them. The details weren't important. Switching it from the labyrinth to Hell, changing the reason they were in there and who their rescuer was makes the story hard to recognize as borrowed from the Death Gate.
So the theme of Auric is ascension. There isn't much actual story around it in 0.34 (thats all coming in 0.40), just the theme and game mechanics. But that would be all they could really borrow. Auric is based in winter with all that comes with it. But a writer isnt going to see that as a part of the Auric story, thats just the setting, and someone who truly did want to borrow that from FfH likely wouldnt carry those aspect over. Which makes it just an Ascension theme, which of course was around long before FfH.