Not entirely wrong, but tokens are not just "fake" in the way, for example, an in-game currency is. They're the fundamental "units" of data, both input and output, processed by the model. For most models, tokens are just a certain number of characters or words. So they're not completely untethered from the model. If we're both using Clankerbot v5.1: Sloppy Logic Edition™️, your tokens are defined in the same way mine are.
This is near the edge of my limited understanding, but AFAIK, yeah they can mess with token costs and billing schemes all they want. They could theoretically charge us 2 different costs per token, or do surge pricing or some shit.
if they wanted to change the actual size/definition of what a token is though, that would require a whole new model (or at least a major revision).