In their case Sign Up goes to an account creation page, and Under Attack? goes to a sales form that (presumably) will page a sales development rep (SDR) to wake

In their case Sign Up goes to an account creation page, and Under Attack? goes to a sales form that (presumably) will page a sales development rep (SDR) to wake up, qualify the lead, and fetch a solutions engineer and sales exec duo. In any case, the implied lesson in the article is to A/B test different ideas and see what works, rather than sticking to the default.