So the news today is that there's a review online of the script, penned by del Toro and Matthew Robbins. Writing for TempleOfGhoul, Dejan Ognjanovic (via Cinematical) delivers a lengthy rundown of what to expect from the movie. It is here that I would advise all of those who wish remain completely spoiler-free to stop reading.
First, it is important to note that Ognjanovic comes across clearly as an unabashed fan of both Lovecraft's and del Toro's work. He admits that what he read falls more in line with pop culture takes on Lovecraft's work rather than the author's work itself; in other words, much of the subtext is stripped away, but the slimy, tentacled mega-beasts from outer space remain. To use the reviewer's own words, "it feels like a 'Hellboy' movie without Hellboy, with a light dose of [John] Carpenter's 'The Thing.'"
He goes on at length to explain exactly what this means; if you're curious, I would encourage you to read the source via the link above. Lovecraft fans should note though-- it sounds as if the story follows what was originally written pretty closely, at least in terms of how the main beats unfold. As the writer puts it, "Scientists go to Antarctica, resurrect primeval monsters, mayhem ensues."
The big question mark is whether or not this is a legit script review. Lovecraft's story was written in 1931, so it's not like there's any mystery about the narrative as far as an adaptation is concerned. This could just be one dedicated fanperson's excited ravings. The writeup also clearly makes some assumptions; at one point, Ognjanovic writes, "There's relatively little stress on atmosphere." Del Toro is pretty well-established as a modern-day auteur. This is a script that he wrote (okay, co-wrote) and intends to direct. And fans know well that it's an idea he's been marinating on for a number of years.
Given all of that, I can see why notes on the atmosphere might not be included in the script being reviewed. And of course there's always the possibility that the script is a fake. I don't get the sense that it is, but you never know on these here Internets.