IIRC during the Trump Presidency it was primarily President Trump himself that made this accusation and it was not clear his source of information-- whether he

IIRC during the Trump Presidency it was primarily President Trump himself that made this accusation and it was not clear his source of information-- whether he had specific information about it or was making the claim out of suspicion or a simple matter of political posturing as part of his more adversarial approach to Chinese relationships. The linked story on the other hand details more specific & supported details stemming from more than a year after Trump's presidency & TikTok's assurances that it was not doing exactly this. In short, what were mostly unsupported claims during <= 2020 have now been significantly substantiated.