I don't think you're going to find peer reviewed studies on something that happened a month ago, but I would be very sure to say someone is working on it.

But if you've used Twitter you can recognize when something changes. I haven't used it for years, but secondhand I've heard it was pretty egregious. Obviously this could be due to external parties heightening a disinformation campaign, but I'm not sure that really matters.

American social media platforms creating an environment where propaganda and misinformation flourish and refusing to take action against it has the same net effect as TikTok altering internal algorithm. Arguing that somehow TikTok is worse because it's a foreign government is nonsense when every social media platform is manipulated by foreign governments to the same effect.

Doesn't help the US government just keeps saying "trust us bro, we have reports that say China is spying on us" while they threaten to ban one platform. Nobody trusts that, it looks like a witch hunt, and sounds racist when they single them out this way.