I’m skeptical that there’s a filter like this over the whole game. If you look at the leaked screenshots none of the others are anywhere close to this dreary (to my eye). Although some of the other images have different issues like extreme darkness/low gamma which makes me think these were never intended for the public. They have also since been pulled from the site (supposedly this was the original location). Maybe it was a look they were testing at some point and then scrapped, who knows.