especially after claiming "There's also a few snippets of code on the Android version that allows for the downloading of a remote zip file, unzipping it, and executing said binary."

I checked quickly tiktok apk, but couldn't find the relevant part.

Most possibly, he is mixing some bridging functions which are mapping functions or resources from dex files. (such as https://github.com/alibaba/ARouter, which I suspect tiktok uses)

such as:

@Route(path = "/test/activity") public class YourActivity extend Activity { ... }