TikTok is not much different than Instagram and Youtube Shorts in the western world.
That it is heavily moderated in China would not surprise me either. But i wouldn't call that an "agenda"
TikTok is full of anti America propaganda. It rarely gets removed. Anything anti China doesn’t last long.
Instagram has hardly any anti China or anti America propaganda. And it’s certainly not recommended to you within minutes of using the app for the first time.
Opened TikTok in Taiwan and almost immediately got anti America propaganda. Blaming America for covid.
Try and question "America's greatest ally ever" and their policies and see how long you last on these platforms.
When critiquing china, remember that you're essentially looking in the mirror.
People generally don't hold ethnic cleansing in high esteem.
On Instagram on the other side, I've never seen any serious amount of political messages, but they all want to sell me merch, cat-toys and nerd-toys from any point of the spectrum. Likely be because they have more information about me. And these days, TikTok is pretty much like Instagram, all cats and nerds and the occasional call for blood from those plebs who break their spaghetti.
So I don't think it's that any platform is full of this or that, but it very much depends on what the platforms think what might be interesting for you, and the rest you just don't see until it really floods the platform hard.