The first thing I thought when I read the abstract of the underlying paper was that this sounds like "model collapse" at the society level.

I don't feel super confident that we'll "soon" find ourselves in a world where there is no variance left in thought (would that be the net effect of total model/epistemic collapse?), though if you do accept that there could be any loss of variance due to AI, perhaps it's not unreasonable to consider how much and how quickly could this happen?

All this is by way of saying, I don't think it's wrong to ask these kinds of questions and think deeply about the consequences of societal shifts like this.