It seems as though the problem affected high-profile players and professionals as well as anyone who signed up. After reports of the issue emerged, EA took down the page to investigate and said it would provide updates as soon as possible. When Engadget asked EA for comment, it offered the same statement it posted on Twitter:
Update 10/4/19 8:46AM ET: EA confirmed to Engadget that it shut down the registration process about 30 minutes after signups went live yesterday -- around 1:30PM BST (8:30AM ET). The company said it found the cause of the issue and has fixed it, promising that players won't see it again. EA explained that around 1,600 players were affected and that's it's taking steps to contact them and help protect their accounts. The plan is for registration to re-open "in the coming days" via an announcement on Twitter.