It's true that keeping track of how many models are out there, like OpenRouter did, is a low-cost way to get some numbers.
But saying that tracking produces the expansion of available models on their platform is a bit too simple, really.
Tracking is just counting; the actual work of adding 600 new models by December 2025 involves developers and business choices, not just observation.
It's like counting how many wedding venues exist isn't the same as actually booking one and putting down the deposit.