She didn't get canceled exactly, at least not in her own region or globally. Like 8 months ago, she was reading out her sub counts on youtube by region (I think it was sub counts, might have been superchat earnings or something). She was literally just reading the page as it appears in her youtube statistics. In reading the regions, she read taiwan and it's sub count. That's it. That's all she did.
This led to massive outrage from china and a fairly large and dedicated group of ultranationalists have been harassing her ever since (death threats, spamming her stream chat constantly for months with bots making it unusable, of course saying horrible things to her on social media, doxxing her, etc). And it wasn't just like random people, there were dedicated communities that planned this stuff. They would also spread this harassment to anyone she worked with, although not nearly for as long.
It never let up the entire time since it happened and a fair amount of people have avoided collabing with her as a result. Despite being the driving force behind the company opening an english branch, she hadn't been allowed by the company to work with them the entire time until recently (which, in retrospect was probably only approved after she decided to quit).
Oh, china also gave an ultimatum to cover corp (the company that owns hololive) to fire coco or withdraw from china. Hololive had a chinese branch and plenty of the JP branch streamed on bilibili (the main chinese streaming platform). Hololive suspended Coco but refused to fire her and ended up terminating their chinese branch as a result and they can no longer stream on bilibili.
Literally because someone read data off their youtube page once. China is pretty absurd.
EDIT: We don't technically know why Coco left. We can gather that it was her choice and that it was decided a while ago from what some other members have said. It's possible that it was entirely from the harassment which did visibly get to her on a few occasions or it could be primarily motivated by something else. She did say she was unable to share her reasons and apologized for that but thats all we know for now.
i see, yeah we can't say for sure unless she herself confirms the reason, but it's logical to assume she left because of the non stop harassment and the effect it has on the company and her co workers who get tangled in it, so we can't call her being cancelled but very shady stuff indeed