They basically got boosted in visibility by a few popular outlets in Brasil. At least one of them had 1000+ views and followers, and most of the people in the comments actually say stuff like "Coming from X's channel!" and similar, so it is very likely this is all legit.
Viewing post in Rating irregularities
we can see the number of votes on the submission page, its 228 votes.
One channel has 87 views on the video with a subscriber number of of 868, subscribers, not much about it.
I believe the most of the numbers belong to Game Chinchila fans who did not vote because they liked the game but their youtuber asked them to do it. Which is the very thing called having a following.
what's wrong with watching a let's play and then voting for the game? You still saw the game. Especially when it comes to story driven games, I don't see why this is a problem. I voted for several games through secondhand experience, either by being on stream with a friend or watching a video later. I don't think these sorts of votes are the ones people are questioning, at least in my opinion, those are still valid.
yes they are valid but the fans are not real, they were told to do something and left. This is common in Kickstarter, steam and social media post. The people who voted will not return to play the game, they were told to do something by a person and then they had nothing else to do for that game. Some might still be following but lots of the fans are just vote and leave kind of people.