This is a little unorthodox. But, a first party cookie that stores consenting data used for reasonably expected purposes, doesn't need to ask you explicitly for consent. [As Hacker News ostensibly doesn't need cookie consent for you to log in with a cookie.]

https://gdpr.eu/privacy-policy/ suggests they share data with third-party Google Analytics, which seems to breach guidelines - except that they respect Do Not Track in this case.