This is a story that has not been officially recorded.
Whether you believe it or not depends on your judgment.

In early 2021, January-March is a difficult time for Kiryu Coco.
Because the only way that Anti can't spam Coco at that time is Opening a member-only chat. Still, there are some Chinese antis sign up to be a member specifically for spamming.

Until one incident not related to Hololive has permanently changed the situation.

Tatsunokos contact YouTube team about the problems Coco was facing at the time.

Make YouTube aware of the problem
This is clearly evident in Kiryu Coco's Twitter on April 14, 2021.
https://twitter.com/TeamYouTube/status/1383314390372347904

Coco's channel has become a testing ground for anti-spam systems.
Coco once said about this in a short sentence that her channel now has YouTube collect spam information.

After Coco's new costume red jersey streamed, No one can spam Coco anymore. Antis spammed peoples Who collab with Coco instead.

https://twitter.com/Fwiz/status/1390439746841681929?s=20

Coco has graduated, but Coco's legacy will forever protect her friends in Hololive.

Because YouTube has started to bring out the anti-spam system that has been tested on Kiryu Coco's channel for other channels to use in the future.

If Coco says she will be graduated from March - April. YouTube's anti-spam system won't happen.

Coco's friends such as Fubuki or Haachama might be a victim of anti spam.

we might think she is confident that the anti-spam YouTube system will be implemented in the near future.

Coco and Tatsunoko's actions didn't just save the Hololive friends from anti spam.

It also helps all YouTube streamers not to face and fear spam problems from China in the future.

As she wrote on a sign in Minecraft

"In the end I am the winner"