None of this is actual scientific research, none is peer reviewed and published. These don't even have the proper form of peer reviewed research. But as you link to Penetrum, their security analysis (which they were paid for btw), has one thing going, even though it's outdated as it's based on older versions. There is reverse engineering in there, so you can exactly see what data TikTok is collecting in the app. Anyone can use Ghidra for this:
https://ghidra-sre.org
You've shown that you do not understand how science actually works by posting articles from journalists and quoting from wikipedia as "scientific". Let me help you a little, as you make the same mistake as the Trump-nutjobs who demand prove that no voting fraud happened on large scale that cost Trump the election, when the only correct way is to prove that it did happen (which they can't do).
In science you don't proof the nonexistence of invisible, pink elephants flying around your head if someone claims they exist. The person making such claims has to prove they exist. A person claiming god exists has to prove it. A person claiming a big turtle is carrying the universe has to proof the existence, not the other way around.
I could just as well claim that you're paid off by Trump to try to convince people on here that TikTok is bad. Then I demand you prove it. If you show me your recent financial transactions as proof and there's nothing on it, I claim he visited you and paid in cash... and we can go on and on about this. The only way this becomes true and a fact is if I can proof that you're paid off by Trump, not the other way around.
This is also true for TikTok, the proof has to be made that TikTok is collecting any data that is not in their TOS. In what world is "TikTok is ok" a scientific statement? What would the corresponding research question even look like? No scientist in the world would research if "TikTok is ok", whatever that even means.
However there are plenty of researchers around the globe trying to find evidence that TikTok is indeed collecting illegal data and sending it off to China. To date, there is no peer-reviewed publication of current TikTok that shows proof that what you claim is happening.
Sure, plenty on non-scientific articles out there claiming one thing or the other, such as this:
https://www.businessinsider.com/tiktok-explainer-privacy-facebook-google-2020-7?r=DE&IR=T
Again, this is not scientific. However it links to a Twitter account of someone who also has a blog and keeps a very close eye on what TikTok is doing when it comes to data collection. Again, nothing illegal found there, only what TikTok is already explaining in their TOS. I'm pretty sure if anyone would find actual proof of something illegal happening, there would be a peer-reviewed publication right away. Until then, this is all paranoid nonsense without any proof to back it up. And again, one has to proof it's happening, not that it's not happening.