Probably isn’t exactly helpful since you want to cut to the chase and get an actual specific channel which reviews short horror. I’ve come across loads. I’ll post back here if I remember some. In the mean time, there may be some from this list of general indie YouTubers which barely scratches the surface if you can be bothered to trawl through it unguided. : /
https://itch.io/t/5481376/an-archived-database-of-mostly-indie-game-youtubersstreamers