Collecting? No. Using Stripe to charge $1 to gate brigading. Unless you think everyone using payment processors on HN are also "collecting"?
You can easily vet the payment flow in the browser console, which is taken directly from the Stripe docs. Also, since there's no data collection, period, there's nothing to unsubscribe.
Please take some time to actually either read the privacy link, or if you are really concerned, inspect what the browser does with your information as Stripe's library processes it with their servers for a one time transaction.