Honestly though Metacritic user reviews have never been very trustworthy for me personally, because even before political trolls started engaging in review bombing the most common kind of troll review bombs came from console or PC fanboys (like I still recall the user score war that occurred when the first Horizon and Zelda: Breath of the Wild happened to launch within weeks of one another).
Plus IMO this doesn't feel quite the same as the Last of Us 2 situation where part of the backlash was people felt the game was overhyped by critics, Horizon: Forbidden West's DLC got positive reviews but mainly 7's and 8's, not near universal 10/10s like LoU2 got. It unfortunately does look like most of the review bombing came from people genuinely upset the DLC confirms Aloy is either lesbian or bi (backing this up are comments I saw on places like YouTube, like where I saw someone who said "the bombing is justified if a dev is trying to shoves alphabets down people's throats" and buddy if the mere fact an LGBT person exists in a piece of fictional media is enough to trigger you that bad then you're literally no better than the people on the exact opposite extreme).