The article on HN only said that they seemed to be collecting this to detect resellers. How else did the behavior change?

Most services I know that are trying to block abuse do collect device info

There is this whole thing where Fable silently starts behaving worse if they suspect you are trying to use it for RL or are otherwise building a competing product. This is likely the primary vector how that works: they check if you are in china, if you proxy your requests, and if you are from a list of known labs or match a couple keywords

regardless of anything else, whether what you said is true or not: blocking program execution based on the detected environment is a runtime behaviour change.