No, CFIUS has NOT been investigating TikTok for 2 years. It was in November 2019 (10 months ago) that CFIUS started investigating TikTok (ByteDance's 2017 acquisition of Musical.ly) [1]
It amazes me that such incorrect assertions get so mindlessly upvoted on Hacker News.
You've written that elsewhere that "Bytedance is a Cayman Islands company, not Chinese. Despite having offices in Beijing, Bytedance and Tiktok are not beholden to the Chinese National Intelligence law", so it seems you might be unknowingly (or knowingly) spreading incorrect information.
The HN community deserves a lot of blame for being unable to filter out such falsehoods.
[1] https://securitytoday.com/articles/2019/11/04/tiktok-nationa...