I feel like the TikTok ban is only the start.
The US is pissed that it couldn't 100% control the narrative on Israel genociding Palestine and sees the internet as the reason why. They've already put a lot of effort into homogenising and controlling the narrative on most big social media sites. I wouldn't be surprised if they started cracking down more under the guise of "stopping misinformation"
I agree on being suspicious of shadowbans as well. However, Automoderator has the ability to effectively shadowban someone from a given subreddit. You configure it to automatically use the "filter" action triggered by a poster of a given username. "filter is a unique action to AutoModerator, and will remove the post but keep it in the modqueue and unmoderated pages." Works on both posts and comments. So it might be more prevalent then we think.