No, it makes sense to secure engagement with the most expensive implementation and then cut costs, this kind of stuff is pervasive in the industry. Besides, we have Brockman on record saying that they do "a lot of quantization"[1][2] so it's not paranoia to suspect other optimization schemes when there's a clear performance drop, which they have also denied a few times.
1. https://chat.openai.com/share/44a0c5b6-c629-470a-992f-8cdbbe...