Social media in general doesn't have the best track record on misusing user data so I would not think TikTok any better despite its protestations to the contrary. I'll grant that access by the Chinese government is not necessarily a given, but we do know that Chinese companies are very much obliged to accede to any commands by their government. Should the PRC have a desire for it, and should they consider themselves to have even a thin veneer of deniability, I am confident they'd make use of it.