Clicking the link should not say anything special when you land on the page (which is rather dumb) but once you create your account you should get double the base free storage (20 instead of 10). I don’t recall them announcing any change in that policy.

Usually, clicking such links takes you straight to the form, with the URL modified with a referral tag. But clicking your link just takes me to the top page, which is why I wondered 🤔