> "The impact of AI is getting undeniable", so, the goalposts are "the impact of AI". Probably something like "the impact of AI is high, or will be soon".
those are not goalposts - that's an incredible vague 'goal'. What are we moving here exactly?
Thus "moving the goalposts" is for the defenders to shift what argument that the other side is trying to disprove.
If the argument is "the impact of AI is getting undeniable", you'd try to show that impact of AI is not that high, and not looking to be that high in the near future.
The other side might move the goalposts by saying something like "well, it doesn't matter if AI is actually that broadly impactful right now, all that matters is whether it's impactful in the field of mathematics". At which point, you might be frustrated because the effort you put into engaging their previous argument is now moot.
PS - yeah, yeah, I overexplained