Your posts wouldnt be blocked, you would have to verify that you have read the article first before posting.
HN is often accused of being a 'hive mind' of users with homogenous opinions already. Making people assert that they've read the article, and understood it within a set of constraints, could remove a lot of nuance and variation.
Plus, I hardly ever read the articles.
Provide the name of a city mentioned in this article.