Fans of MCYT, which stands for Minecraft YouTubers, often occupy the trending spots on Twitter. Sometimes, multiple times a day with multiple hashtags. 

If MCYT was a topic, it'd show up above the trending hashtag. This would make the entire trending tab neater. This also allows people to block MCYT if they wish to not see it. Fans of Minecraft (the game) can block it without having to block the Minecraft topic altogether. Often, things that are only indirectly related to Minecraft can show up under the Minecraft topic (i.e. tweets about Minecraft content creators playing Among Us, despite the lack of actual Minecraft content). 

Right now, MCYT-related discussions are listed under "gaming" or "Minecraft." Having a separate subtopic, such as how K-pop is a subtopic of music, would give fans of MCYT their own space without encroaching upon the spaces of others.