it's not difficult to prove. In the wake of the tarrifs, everyone in the US got Chinese manufacturing videos pushed to their feed so customers can buy direct from factories and avoid huge markups by a middleman.
I don't think Occam's razor applies here. Before the tarrifs, Donghua Jinlong glycine going viral was a silly Internet thing, but the tarrifs are big business and it might come off as a tin foil hat theory that the CCP exerted control over TikTok to push videos that undercut American companies in the face of American tarrifs, but geopolitics is very big business. Believing that those videos came up organically seems naive because this shit is a big deal with far reaching global ramifications.